Cell C - No refund or credit for wrongly billed (four months and still not sorted)

We as a company are very disappointed in the service receive from Cell C. We have been with Cell C for several of years and have a few contracts with them. In July 2021 there was two numbers billed to our account, that we didn't authorize and these numbers were unknown to us. We immediately, after receiving the statement with the invoice billed which was paid by debit order, informed Cell C about this - there are no more Cell C walk in shops in Bloemfontein nor Ladybrand. So, we called the customer services and emailed Cell C. After numerous of telephone conversations and sending emails, with different attachments, letters on our company letterheads, the matter has still not been resolved, but just extra costs doing these calls and communications. It has been four months now; nothing has been refunded or no credit has been made for this. We did as they asked with the letters and bank statement for proof, sent everything to the complaint department and to *****. When we phone the customer services and speak to a consultant, they do not even have access to the case references loaded for this case reported, as there were plenty of case reference numbers sent to us, but Cell C customer services consultants do not see any case references for our account. This is unacceptable to be billed for numbers that is not yours. We will never refer anyone to Cell C. We rate Cell C services - extremely poor!