Blocked my account for money I never received

My bank account got blocked it stated they blocked it for my own safety and I should call them then they will unblock it on they side I called them and the agent states my account got reported for funds I received and she stated the amount aswell but then she said the person reported my bank but now the thing is I did not receive any funds with that amount stated and the only person who send me money on that day was a friend of mine so now I don't know what do to because they want an affidavit and proof of payment but how will I get a proof of payment because the person who they claimed reported my account never send funds to my accounts and how will I get a proof of payment of that person if I did not receive money from any other person than my friend now I don't know what do to because I can't provide details because I don't have the details which they stated I never received the amount they mentioned I have money in my account which I need because I have kids that has to eat