Capitec insurance is a nightmare

I have an existing funeral insurance with capitec bank, early September I decided to add another member to my cover. The original premium was R108, after adding the member it went up to R900, however capitec decided to only debit the original amount of R108. I tried reaching out to them to have this corrected but I'm not getting any joy. I'm afraid that during claim period I'll have endless issues because of this. I tried every way possible to have this fix but none of their staff bothers with resolving this. CF***1