Defeated By Bad Service from FNB

I run a small business and had funds coming from Nigeria. My depositor sent through the funds and FNB rejected the funds and sent the money back. I inquired with them (FNB) and provided the proof of deposit only to receive a response that i need to get the fund processed again.

3 Weeks later the funds are then processed again, i get a proof of payment and email it to the FNB team on the 16th of Nov to please look out for the transaction. I don't receive any response, I follow up on the 22nd of Nov only to be told that the funds have been returned to the sender for the second time on the 21st Nov.

How