Telkom's Poor Service

I am utterly disgusted at the service. Spoke to a consultant on 3 September 2019 to change my banking details, the consultant made a note of it but never saved it (this I confirmed at a later stage with a different consultant). They didn't debit my account and I made a manual payment. In October the same thing happened, no debit order and I missed it. Come Beginning of November I call to query why it's because I failed to make payment when it was their idiotic mistake. Make another manual payment but short of a few rands. Now my account is locked and suspended due to non-payment yet it's their mistake not mine. Been with them for a couple of years and never once did I miss a payment (I mean like a good 5 or 6 years) and now I am sitting with no phone and not abe to do anything.