Telkom Billing

Telkom has to be the worst cellphone service provider. My debit order bounced back on the 28th of December as the amount was short due to telkom deducting more then they supposed to. However I made an eft payment for that amount and on the 26th of January, the January payment was deducted. To my understanding my account is up to date. I called in as my invoice shows a total amount of 1677.00 and I spoke to an agent who said this will be sorted out. On the 4th of February Nudebit deducted R157. 00 from my account and reference was telkom. However I do not understand how it is a debt as the amounts were settled. I went up and down to a telkom store and they advised they can't assist as only the billing department can and they only assist via telephone. I will not allow them to deduct 1600 or whatever from my account. Should this continue I will cancel all services because this is bullshiit.