Double deduction

I sent my application to join Discovery on Feb 22. Heard nothing from Discovery, so I phoned them and an operator told me there were problems with my paperwork. Fixed the problem and only in March did we get confirmation that we are covered and what our policy number was. Discovery did not deduct for March. No operator told me how the billing works, that I could manually pay my fee in March. We claimed once on March 22. Now Discovery, once again not caring about their clients, deducted two months in one go. They refuse to assist me as they 'are in the right'. Instead of warning me this might happen and giving me solutions to a potential problem. For this reason I regret re-joining Discovery, they are unwilling to assist their customers and frequent 'mistakes' in their billing and processing.