Never upgrade but increased premium

I was on a medical aid with my ex. I spoke to a person in the call centre to transfer me to my own. He advised me to go over to a different plan, but since that can only happen once a year, that could only happen in January. For the month of December I was put on the same plan, just not linked to anybody. Then Jan I would be transferred. Only thing that happened in Jan was that I paid the annual increase. Now they say that there isn't even anything about this call on their system. If they can't even get a little thing like this right, how can they provide proper service when needed.