Poor Service

I opened an account at Cell C Fourways Mall in February 2022 where the consultant made a mistake and added me to a more expensive option plan of a 10gig top up instead of a 2gig top up contract. This was immediately rectified while I was in the branch. 2 Weeks later I received my monthly statement indicating that I had to pay for both contracts, I went to the branch who then assured me it was before the systems were updated and I will not be billed both amounts. Needless to say I was billed for both contracts and to date I have not received my refund, after numerous store visits (Where no one can ever assist and the manager never there) It has been "Escalated" for the past 3 months and sill no outcome. I am not receiving any feedback from the branch, I have been there numerous times and all of a sudden my calls are not being answered anymore. After pleading with the manager last week for feedback, it has been 7 days and no feedback whatsoever.