BILLING ISSUES FROM THE SUPPLIER

I am a customer of Discovery health, I joined the Medical scheme in 2013 July. The company I worked for then was responsible for the payments of my monthly premiums, they would deduct the money from my salary before they paid me. In 2015 July I left the company and had to now pay my medical aid on my personal capacity. I paid them from the 25th of August for my August premium. In September They deducted my premium and reversed its again hence I was behind in payments and I lost my job then because we lost the client and I had to go. I went on to find another job and they use the same system as the previous company which is pay for my medical aid from my salary before paying me at the end of each month. In November I settled the outstanding September premium and sent them proof of payment. Even after joining the works group medical aid they still continued deducting money from my account. They then reversed a payment in December and now they have suspended my account again claiming that they reversed money, that was not my mistake. In September also they reversed that months premium hence I was behind with payment, a mistake on their part. Please help