Try to cancel dstv products insurance but find no assistance

Bad product insurance trying to cancel my product insurance of more than 15 years paying for it my decoder is still working well I don't know how to get help, their agents of online it's like they don't care about that side of insurance they say call a certain no. I received email with pdf attachments saying my insurances are both canceled with immediate effect which is what I want but on my monthly bill it still appears and included why is that, if I don't get help I'll cancel all my subscription, and install fibre this is exhausting