Wesbank

Good day. We bought a bakkie through Wesbank in April 2018, we signed on the contract that the debit order MUST go through the 1st of EACH month it only happened once or twice we went in arrears and they increased our monthly payment from R5200 to R7200, not once they put a debit order through of R7200. Early in September they phoned my husband saying the bakkie was not payed for September, we went through the statements NO debit order was put through one week after that another lady from Wesbank phoned him again asking what was going? He told her that they didnt put a debit order through and then she said the debit order was CANCELLED on our account WITHOUT even letting us know. Now we are in arrears AGAIN!!! What should we do regards this?