Paypal mysteries

From a customer I got this error report:
"Das Produkt wurde mit PAYPAL bezahlt (Bestätigung per mail habe ich erhalten). Allerdings bei Ihrem System wurde die Bestellung abgebrochen, wegen Zahlungsfehler."
"I paid by Paypal and got the confirmation by mail. But your website reported a payment error"

We got the payment in our Paypal account, but there is NO record in the CBSubs database!!!

This is a very odd behavior that payments could be completely disappear. In terms of money a system should NEVER forget any payment related or order related data ...

We recieved money from many customers but some experience problems like that!

Version: Joomla 1.5.25, CB 1.7.1, CBSubs 1.2.2

This can happen if the user never returns to your site (so PDT can work) and you don't have IPN configured. This can also happen if the user never returns to the site (PDT) and IPN is misconfiguration so it doesn't arrive properly. Do you happen to have a failed IPN in your IPN history within your PayPal account or any notification in CBSubs Notifications regarding their subscription?

@krileon

PDT and IPN checked (your software states to send correct return urls with every purchase, so what could go wrong here?), nevertheless it is ok.

A secon user has the same problem, the log stated 'item mismatch'. Interestingly, paypal credited us 31.80 but CBSubs stores internally 31.7924

In an earlier bug report, I reported that there is a math issue within CBSubs. I don't know, why you store the amount internally different from what you send to paypal or other Gateways! Why do you not round the amount and then store it???

Another hint:

Could it be a umlaut-issue in the address fields? Interestingly, the user stored the street "Brühl..." in the field, but in the error report the street was store only with "Br " ...


*** This is the error log of the disappeared basket:

Dies ist das vollständige historische Log, Änderungslog, und Fehlerlog.
Ereignistyp: Fehler-Log
Ereigniszeit: 23.12.2011 17:23:07
Nachricht: Received back from paypal: cbpaidsubscriptionsNotification::__set_state(array(
'user_id' => 3635,
'notify_version' => NULL,
'verify_sign' => NULL,
'payment_basket_id' => 258,
'payment_method' => 'paypal',
'gateway_account' => '6',
'log_type' => 'R',
'time_received' => '2011-12-23 16:23:07',
'raw_data' => '$_GET=array (
\'option\' => \'com_comprofiler\',
\'task\' => \'pluginclass\',
\'user\' => \'3635\',
\'plugin\' => \'cbpaidsubscriptions\',
\'cbpgacctno\' => \'6\',
\'cbppdtback\' => \'xxx\',
\'cbpbasket\' => \'258\',
\'result\' => \'success\',
\'cbpid\' => \'xxx\',
\'tx\' => \'XXX\',
\'st\' => \'Completed\',
\'amt\' => \'31.86\',
\'cc\' => \'EUR\',
\'cm\' => \'258\',
\'item_number\' => \'S7198-3635-33\',
);
$_POST=array (
);
$transaction_info=\'SUCCESS
mc_gross=31.86
invoice=U261041682790849
protection_eligibility=Eligible
address_status=unconfirmed
payer_id=XXX
tax=5.09
address_street=Br
Betroffene Tabellen: Benachrichtigungen
Tabellenschlüssel: 251
Ändern:
Ändern:
Benutzername: XXX
Voller Name: XXX
Benutzer-ID: 3635
IP Addresse: XXX.XXX.XXX.XXX
Log Priorität: Fehler
Log ID: 31585

Maybe I got more insight into the problem. We have a plan with a regular price of € 41.18 plus VAT (€49,--) and on that we give discounts up to 50%.

One customer got a discount of 46%, that leads to a price of €26.46 incl. VAT in CBSubs, but in Paypal the user has to pay € 26.47! These users have problems with payping baskets via Paypal.

CBSubs store VAT of € 4.22507 but Paypal calculates € 4.23.

This is a rounding issue and it is absolutely not understandable why CBSubs store internally with a precision of 1/100000 instead of 1/100!!!

Thanks for your precision, that helps.

CB stores with 5 digits to take care of all currencies worldwide, and to avoid many other rounding issues that you usually find in carts.

However all Paypal payments and compares for checks ARE rounded to 2 digits so that is most probably NOT your issue in the Paypal payments failing.

Please check your Paypal settings following precisely the CBSubs manual which has detailed instructions for setting up PDT and IPN, or open a ticket in Support->Open ticket menu to ask our team to check your settings (site-side and paypal-side) next week.

Hi Beat, thanks for answering on a holiday ...

I checked the configuration many times, and about 50-60% of all Paypal transactions work. But there are some, like I stated above, where it comes to a difference between the VAT stored and computed in CBSUbs and in Paypal.

The test basket contains the following items:
- product = € 41.18 net
./. Activity coupon 46% = € 18.94

Sum to pay € 22.24
+ VAT € 4.23

Overall gross payment € 26.46 (???)

You see here is the rounding problem as if you would compute the items manually from the invoice the gross amount should be € 26.47!

Internally, CBSubs stores the VAT with € 4.22507 and the gross with € 26.46227!!!
This happens because the net with 5 digits is € 22.2372 (that explain the rounding in the invoice upwards), also the VAT rounding upwards (because it is > 4.225)

If these values are forwarded to Paypal, the customer has to pay € 26.47 but CBCubs "expects" due to the invoice € 26.46!

This is definitely not a configuration issue, it is related to the rounding in CBSubs. I suggest to round all values one time when the payment basket is stored and then never to round numbers or parts again.

As we are in a holiday sale we urgently need a fix. Thanks for your support.

Manfred