MEDICAL SAVINGS BENEFITS

I recently went to a Dentist for a crown. when I received the claims statement it stated that I am left with R600 medical aid, from now on any other medical things I must pay cash for. I joined this medical aid on the premise that, there is R15 000 threshold for cosmetic dentistry and R3800 for optical benefits. I am now stuck where this year I need to renew my glasses and I cant. I find Discovery's billing structure highly prejudicial and misleading because had it been made clear to me that I will pay optical and dentistry from my already small savings I would not have joined! to access the Self payment gap I am told I must pay cash. the amount I pay monthly to Discovery versus the services I get fall very short of each other to say the least. why is money going towards Self payment gap& Above threshold benefit if to access it you must STILL pay cash! this is ****************!