Why can't I make in App purchases within a game after a certain amount of purchases have been made? This has become very frustrating and I was told to contact Apple Support by King (Candy Crush and Pet Rescue Saga games)

Both myself and my daughter play Candy Crush Saga and Pet Rescue Saga...I know, it's silly...these are just games but for me they're non-responsible, easy and fun ways to de-stress. The problem is, when we try to make purchases, sometimes we can and sometimes we can't. All of my information is up to date (credit card, etc) but I get a message stating the purchase could not be made and to contact Apple support about the issue. Of course when it happens, I'm literally on my very LAST MOVE and then have to 'give up'. It's really frustrating!! PLEASE if anyone has this issue, can you help me resolve it or advise of a work-around? Thanks so much!