Your Cell number could not be YOURS!

I purchased a new blackberry which does not take the normal standard sim cards so I discover that I have to do a sim swop to a smaller sim card in order to use my new cellphone. I visited Shoprite, Ackermans and Pep in the phoenix plaza and all these stores could not help because their policy is to Rica a new starter pack before issue of a swip swop can be processed. I called Cell C customer care and the lady explained that I should visit a Cell C outlet. I visit the Cell C outlet in the Phoenix plaza to follow the process and had a shock of my life as she said that the number I am using is not registered on my details and I need and Avidavid in order to do the sim swop. I Rica'd my number 4 years ago at the PEP store in Phoenix and I am amazed at the type of system that Cell C has that some confusion took place and My number that I have been using for 4 years actually belongs to somebody else.This is the worse aspect to discover! Now I do the avidavid and every time I visit the Cell C store in Phoenix to get my sim swop done, the store is closed and opens on their own conveinence yet all stores open at 9am and this places me at a huge inconveinence. WHERE IS THE SERVICE?