Nedbank not sticking to arrangement

Good day, my husband has a person loan with Nedbank that he is struggling to pay off due to Covid & me not working he made a arrangement with them to deduct an amount we are able to afford . In December they deducted almost 10K from his account & that was not the arrangement with them. We are not able to pay our rent due to this, can anyone please assist our landlord is on our case. ,my husband contact nr ***