****** trying it on a wrong person

Worst medical aid ever, I joined the scheme on January 2022 at which I had a 3 months waiting period. So my first debit was on the 07 of January and again I was debited twice again on the 25th of January 2022 (twice in a month) and they reason is that they debit in advance for February it does not make sense at all, so I decided to cancel my membership with them on the same month, and Note I haven't used any credit since I was on a waiting period. Now they saying I owe them. What do i owe them for? 1st I haven't used they credit 2nd I was on a waiting period. So what am I owing them for?