Discovery Double/Advance Billing

I signed up for medical aid cover from Discovery around the 28th -30th of April 2018, I chose Discovery because I've heard mostly good things about them. My problem is not with their service but their billing system which has put myself and my dependant in a sticky situation. As I have mentioned, I signed up at the end of April 2018, I was not told that the customer will be billed in advance thus I was under the impression that because they did not bill me at the end of April for June, I would be paying for June at the end of well June... No... They billed me for June and July... That is a lot of money... It is now nearly the end of July and I will be billed for 3 Months only having been covered for 1 Month! as they nicely suspended my account since the beginning of this month. I find this ridiculous. At least offer some kind of support to your customers in cases like these as not everyone can afford to pay R8000 for medical aid that was used for one month only and to pay it in one shot. I feel harassed in this regard and I probably will cancel if Discovery can not find common ground with me on this subject.