MTN upgrade ****

Received a call from MTN to upgrade my contract on the 27th of November. My contract fee was meant to be R499 however I received a bill of R1 321.25. I logged a query on the 17th of December and to date nothing has been resolved. Apparently they cannot find the call recording where the consultant promised my contract would be R499. During these difficult times nobody has the funds to pay such exorbitant bills.