Unsure of Medical aid number

On the 29th November 2015, I went to checkers Pharmacy, When I used my medical aid card, and I was told the number on the system is different from the one on the card. And the system shows that I belong to Bonitas medical aid scheme. The same thing happened today (30th November 2015)when my mother was consulting at Tshepo Themba hospital in Soweto, also when I was getting medication from Tshepo Themba pharmacy I was told the same thing, that the number on my medical aid card does not correspond with the one on the system. I am really disturbed as I have been with Medshield for more than 10 years. Can they explain this unnecessary inconvenience which sometimes leads to unnecessary delays in accessing treatments.<br>