Discovery Health will try get your last cent

I joined Discovery Medical Health as it came highly recommended., biggest mistake of my life. I paid diligently every month, hardly went to the Dr. One of the few times I took to my son to the Dr, i was told i don't have money in the medical aid, I took my last few Rands and paid cash. I then told my wife to cancel because it was useless medical aid. Now they are harassing me saying i owe them as if i took out credit. I am not even eligible to have credit, i spend past years clearing myself of debt, now discovery wants to ruin my life. The person that called me is even claimed to be from ITC but did not know nothing about my credit situation, which means they ****.