Telkom lack of accountability

My debit order bounced and I made payment. I have a account with multiple sims and one as designated sim. Now Telkom keeps sms’ing all except that money is due except for me the designated person that the money is due. I asked the lady why and she blamed the back office and said it’s not her problem. I have 2 issues: 1. They take forever to acknowledge payments 2. This is my main one that they contacting all except me the designated person