Billing query and claim for repair.

Cell C, This network company have many useless delays in helping customers. I submitted a query regarding my contract billing October 2020, until today the issue is not yet resolved. I sent my phone on the 1st of February for repair claiming from their insurance, the phone has been there without being attended saying they were waiting for me to give them IMEI numbers. The worse part they did not contact me for the IMEI number they say I should have called to follow up on my claim. How the hell on earth will I know they want the IMEI number if they don't call or send me and email. Their service is so inconvenient, and very poor customer treatment.