Telkom billing problem

On the 28th June 2025 I received an sms stating that I should make a payment since they couldn’t debit I paid the amount which is R320.51 since I saw that they didn’t debit, on the 30 June received an sms notification from bank Telkom has debited, so now I have made 2 payments for June, I tried to call to assistant on my issue, On the 07th of July receipts an invoice stating I should pay R852.80 on top of me paying double amount for June. On 15 July I saw on my bank app that they were trying to debit again luckily didn’t have that amount they wanted to debit, now I am trying to call them they are not picking up my phone call.