I just got a Mali uromastyx and he doesnt want to touch his food. and he is soo scared, i cant even pet him!?

a 250 and a 100 on a 50 may be making the cage too hot w/out a cool end. Make sure you have the correct temperature and that he has a place to cool down if needed. I wouldn't use sand as a substrate for a uro. The very best bedding for a uro is millet. When the uro poops, the millet sticks to the poop and also you won't need a bowl for millet seed, they can just eat their bedding and it won't be harmful to them. You also didn't mention a UVB bulb and that is very important to have w/ a uro. You need to purchase a UVB bulb right away, probably a 10.0 if you have a 50 gallon tank. Uro's won't eat fruits a lot of time so you may not want to offer mango so much. try different greens if the ones you offer aren't working. Mine love dandilions and pok choy and even the dandilion flowers they cannot resist. also try beans like lentils and lima beans and split peas or veggies like squash or green beans. Instead of petting your mali in the cage, pick it up first and hold it in your hand. It should become less defensive then. also don't be afraid of it. They're small and the tail whip will not hurt. You have to be confident when handling reptiles and they will sense your confidence. So first check your temps, then get a UVB and I would expect the uro to start eating. here is a good uro website. I wouldn't ask any more advice from your petstore, a lot of times they just try to sell you products that you don't need or aren't good for your animals. www.deerfernfarms.com