Refund from DStv

Join the price lock on May thinking having a debit order will make my life easier, on 03/09/2019 they debited m R715 instead of R519 worse part of it I didn’t have that kind of money in my account n now the bank cause they paid the extra amount to them they charged m R125 now my account have -318 called them on 04/09 no feedback called them again on 06/09/19 they advise will give m feedback by end of business on Friday till now no feed please assist