Bad service ever Telkom

I took a contract fone last yr Oct, frm that time till Feb my debit orders has been fine which was 299 a month. End of much Telkom didn't debit the money cos my debit order is on 1st of every month. I tried to call them but all their fones keep on ringing no luck of finding any consultant, on the 14 of April they debited twice the money. Then after debit after 2 to 3 days they send me a msg that the debit is for much & April, I was angry cos it wasn't my fault that they ddnt debit the money. Again, may the debited 501 on the 30th not on the date that we agreed on.when I visited their branch the consultant told me that the reason why I'm paying so much is bcoz I'm on arrears. So I feel like they don't do their debit on time so that they can over charge you. From 299 now I'm paying 500 something a month,with same data & airtime. Really bad service