Extra fees on unsuccessful debit order and bad customer service

In March 2025, I had sufficient funds in my account to cover the debit order. However, the transaction was declined with the reason “insufficient funds.” Despite this being an error on their side, I was charged additional fees for the unsuccessful transaction. I immediately contacted customer service to report the issue and was assured that it would be escalated to the relevant department, with a reference number and a call-back promised. I also sent my bank statement as proof to their email address but received no response. After following up via email and receiving no reply, I called again, explained the situation from the beginning, and resent the supporting documents , still with no response. As a result of their failure to resolve the matter, my contract benefits have been frozen, and my credit score has been negatively impacted. This has caused unnecessary financial and personal inconvenience, despite the fact that I was never at fault. Months later, i have not received an email from them explaining what happened or a call. They are silent