Vigin active

Can anyone advise me on what to do, I was a member of vigin active many years ago while I was still stay in Pretoria north I relocated in 2012 can't remember which month and when I left I mad sure that they know about my relocation by telling them but right now their lawyers are busy harassing me about phone calls telling me that I owe them and cannot even send me any paperwork to that I owe them. Can you please advise me on this one