My money got blocked for no reason!!

I borrowed someone R20 000 about 2 years back and he promised to pay me back R23 000. When he payed it back in my account, they freezed the money and I was unable to use it. I did go to the bank and explained to them, even have an affidavit with me and I have been following them up since then but even to date nothing has been done about it. Please assist on this matter if possible Name : Mahlomola Mmamoshi Contact no: ***