STAY AWAY !!! This is why we changed medical aid

We were on Momentum medical aid during 2014. We changed to another medical aid beginning 2015. January 2015 we received a letter from Momentum that we owe them more than R2000.00. I immediately phoned them and queried it. Then they send us a letter that we owe them R660.00. I again queried it, because we paid for all expenses as from March 2014 anyway, there was no monies that they paid. Where did this came from - they could not give us an answer. February we received a letter, oweing them R330.00. I again queried it. Then we received a letter with a statement that they owe us R330.00 which will be paid to us on 19 February 2015. We did not receive that money. Phoned them again. They said it was paid in. I send them the bank statement showeing that we did not received any payment. Phonecalls costs more than R300 already. Then they said no, it will be paid over on 19 March 2015. Still have not received any payments. Then they said no, we owe them R194, and they will email the statements. Still have not received any proof of any money that we owe them, nor any payment. Received the one ref nr after the other. Every one has another story, and we have not come anywhere!