Payment posted to a wrong BP.

Hi experts,

We have a situation were the payment came from a B2B customer and was posted to a Domestic customer.

I check the payment lot, in the selection criteria there is BP and Bank account number of the B2B customer mentioned but the document has been posted to another Domestic customer....

I am zapped by this situation,this is very strange because this is not something that happens by a standard payment prog. Can someone tell me a situation when this can arise, or where can i check to find a root cause....

Thanks in advance.

regards,

Priyanka