One thing that struck me:
I don't believe that the bank was someone able to solve and transfer your money the balance reflect in your account in 10 minutes after not being able to do in 2 days, you said he had proven that he had sent the payment with documents, by chance can you compare the proofs with the current transfer as I tend to believe that as in many cases he didn't pay at all the first time and only under pressure and maybe because of a good fluctuation in exchange rates he agreed to do so!
Network congestion maybe the reason why the money didn't reflect to your account the very day that the money was sent to you but on seeing two different dates when you got the alert, this clearly means that the sender sent the money on the first date but it reflected on the last date which you got the alert.
Banks usually have network issues and most times people lose their money because of this issues because atimes the sender may be debited but the person whom the money is sent to won't be created but after some time when the receiver may not be around the sender again because it will always be said that the money will reflect later since the sender has seen debit alert, the money may be reversed to the sender and the receiver will be at lost since he can't get his goods or the money for it again but when it comes to p2p transaction, it is advisable to always confirm your money before releasing your Bitcoin.