Upgrade - Decline

I have been trying to upgrade my current contract from the 10th of December 2017, just to be told that the application is declined. I have spoken to Anna who put the phone down in my ear, I have spoken to Rachael, I have spoken to Selishia. I was told to phone the legal department as according to them I can not upgrade due to default on account, but surprise surprise my account is up to date, According to the bank Cell C deducted the debit orders off the bank account earlier than usual and that is why the debit order didnt go through. I made both payments as soon as the debit order came back. Come December, the debit order goes off as per normal agreement. Now Im being penalised. Even though my account is up to date. So eventually Im told phone the legal department to rectify the status on the account. I speak to Nduduzi, he assures me that the status has been updated and I can reapply for the upgrade and it should be sussesfull. Well guess what. It has been declined again. I have had this contract for 6 years, my previous contract I had for 8 years, so all in all I have been a loyal customer of Cell C for 14 years and this is the kind of service I get. I'm seriously considering cancelling my contract and moving to a service provider that wants me as a customer.