Coins are trouble!

Love the game and play every day but as soon as you get coins you have to spend them to receive more (quests). Im probably going to get my 1000 coins for writing this review, and than a new quest comes up and I have to spend them, I get a reward and have to spend that on another quest... It is keeping me steady at... Broke! I have a few gems, why cant I use these to buy coins?!

Not much to do about Happy Zoo - Wild Animals, v1.6