*** service provider. Telkom should burn to the ground

my contract came to an end on 26 Jan 2022 i made a call two weeks prior to the date to cancel. I was advised the contract will be cancelled and my request was to keep the number on prepaid. My debit date was the 25th so Telkom decided to debit my account for R59 on 25 Jan but there was no money so it was unpaid, so my bank charged me R115 for this. I then called Telkom because the line was suspended i was advised to pay R59 to open the line and i paid this in cash. Then Telkom sent me a bill of R202.68 so i called and i was advised this is a charge for a missed debit order and the same charge was billed again in Feb so now i have a bill of R405.38, so is this legal??? Is this fair trade or fair practice, who can i speak to???