Service needs to improve drastically!!!!!!

I am extremely disappointed in Telkom's poor service. Recently I was billed extra for a sim card which I did not order, which resulted in an inflated bill for January 2021. I contacted Telkom, making them aware of the "error". I was allocated a case number thus concluding the matter and I was informed that the refund would reflect in my bank account within 5 to 7 working days. The funds are still not reflecting in my bank account after almost 11 days. I contacted Telkom once again regarding the refund and I was instructed to provide them with a bank statement as proof that the refund hadn't been paid. This I find very unacceptable. Telkom is going from bad to worse. Will definitely change my SERVICE PROVIDER. FED-UP!