Bad service and withholding information to customers

Telkom doesn't clearly train their staff sufficiently when it comes to selling new products and providing sufficient information to new customers. Took out a new contract phone with them on the 14/04/2021 and was sold insurance in conjuction with the phone for R120/month. Imeediately after leaving the shop i get a call from a insurance company claiming Telkom called them and they confirming my details and that insurance would be R109 and not the R120. Anyway first forward to 6 May 2021 i get a invoice reflecting R120 only to find out that the phone is insured with Hauweii care and telkom. I immediately went to the shop and requested a cancellation, but was given an email to request cancellation which i did and got a cancellation letter. Then when my debit order goes off i see that they included the R120 and after emailing them yesterday they told me a long story about being billed in arrears and that they would still debit in June. What bull is that because the phone was not even a month and was not even properly explained to what was going on and am seriously considering reversing that amount because even on my debi check i never agreed for that amount to be debited. I need a refund for my R120 immediately before i cancel the damn thing.