Billing enquiry

My experience with Rain has been extremely disappointing. Their communication is terrible. I've called their official number multiple times, and they keep promising to call me back but never do. End of January I took a Rain 101 contract. The agent who assisted me activated a sim card which has not been in use form 2019 without my knowledge or consent to do do. From February to date I have been charge for something I am not using. I called the call centre on 21 June and spoke to a team leader Gail, who promised to take it up with the billing department to refund me what was wrongfully deducted and cancel the sim. This has not been done because another debit order went off today of an incorrect amount.