Upgrade requested without account-holder's permission.

I found out on Wednesday that someone has made an unauthorized upgrade on a contract that I wish to cancel. The contract expires on Dec 11 2018. On Wednesday I found out that an unauthorised upgrade was requested.

On Thursday I called Cell C requesting to cancel the upgrade. They gave me a reference number of ********** 419.

So now I need to cancel the upgrade first and then only can I cancel my contract. I made a follow up with Cell C this morning by calling to find out the status of the cancellation of the upgrade. They bounced me between about 6 departments with no one taking responsibility until I ran out of airtime (called from my phone which is Vodacom).

My worry is that as the upgrade request in the first place was unauthorised by me the account-holder, what's preventing someone from still upgrading the contract or renewing the contract that I want to cancel??

Can Cell C please sort this out ASAP. If this upgrade goes through or the contract (which expires in Dec 11) goes to a month to month contract, I will have no choice but to cancel my debit order.

I WILL NOT PAY FOR SERVICES THAT I HAVE NOT AUTHORISED.