********** monthly premium and not covers for it

I resigned from the above Medical Aid on 31 March 2015 and received written confirmation (BANKMED LETTERHEAD LETTER) that my membership is termination from 31 March 2015. The Supplier however deducted a premium on my April salary whereas I was not covered. I went to the chemist in April and was told that my medical aid has been discontinued. I have today contacted the medical aid and their membership department (Jennifer Pretorius) informed me with arrogance that they will not pay me my premium and I must wait for my savings refund. I demand my April premium as I had to pay cash in April at the pharmacy when purchasing my repeat and did enjoy the benefits of the medical aid on that month. My medical aid card was not working in April. I WANT MY MONEY PLEASE PLEASE