Cancellation of medical shceme

I submitted my request to cancel my membership by September but received no confirmation from them. Every time that I try to follow-up, they say I need to send the request to a new email address or a different one than I did before. I paid them in full and sent the POP, and now I have to resend it to another email address than I originally needed to.

This is ridiculous!!!! I need an answer and help ASAP! I can't afford two medical schemes at once!!! No one helps me!! When I call or contact them, I only get the answer "Please email it to us"! ***! It is unacceptable!!!!