Bad and misleading service

I have cancelled one of the dependants on the 1st of May, giving 30 days notice. They refuse to cancel the dependant at the end of May and will only cancel it the end of June, requesting that I pay for May and June still. The dependant is going over to a new medical aid as of tomorrow and you are not allowed to be on 2 medical aids. Everyone I have spoken to in the call centre has assured me that the dependant will be off at the end of May. The call centre agent today said that it will not change and the other medical aid will need to move my date.

I have phoned multiple times in May, because I do not get any correspondence back. When I talk to the agents it is either call back in 2 days then we should have received your correspondence or, wait for the correspondence, ensuring me that the cover will be cancelled at the end of May, because the original email was sent on the 1st of May.

My medical aid nr is ***.

The were very quick to take the dependant off when they did not receive the affidavit (within one day), but they can not cancel the dependant now