Please cancel this CONTRACT , change to prepaid

on the 2nd of November i walked into Telkom mobile southgate to cancel my contract which was due for upgrade as i was not interested in upgrading, after waiting for an hour queuing , the lady who assisted me told me that she cannot finalise a cancellation at the branch, however she has logged the cancellation on her systen and sent a notification to their Retentions department to call me and finalise the cancellation. she advised that they would call me within two to three days, two weeks went by and a gentleman called to try and upgrade this contract , i told him i wasnt interested and have already requested cancellation, i asked if he could please cancel since he is from retentions and told me to go to a branch near me and cancel there as he cannot assist me from the \upgrades department". i have been to the store and was told that the case is logged "