my account is blocked for 255 rands and i have given all proof but nothing has been done

Standard bank block my account because someone send me ordinary R255, the reason for person sending me this money is back he bought bitcoin from me, i gave him the bitcoin, i have all proof, i send the proof to the bank, including police affidavit , the ID copy of the person who send the money, all the conversation . but till now, standard bank still block my acct, i have money in my account that i need to do my day to day activities, to pay my rent, to buy food, to pay medical bills, to continue my business, to pay my kids school fees etc. they block it since, i even ask them to remove the R255 and put it on hold so i can continue using my account but all in deaf hears, can you please help me ? as it's getting serious and i don't even have money to buy airtime anymore.