Poor service towards client

Dear Telkom Customer. Payment for your mobile service is overdue and will result in an interruption of your service, credit bureau listing and collection by attorneys. Please make payment using reference: ********** ********** 05030 for R 71.90, alternatively refer to https://apps.telkom.co.za/alpha/public/register for Online Payments and ensure quicker restorations. Ignore SMS if you have paid. Now they want to debit some money for something that I don't owe. I tried to contact them still they wouldn't listen.