Okay, you will need to get a lower heat bulb wattage. around 75w should be fine and wont heat his basking or hot spot to unbearable temperatures. It will also give you the opportunity to keep the lamp on all night so that the temps dont drop so low. Heat pads are the best for ball pythons as long as it is running on a thermostat.

The hamster might be the problem. Unfortunately ball pythons have an extremely bad case of addictive personality and some prey is more addictive then others like hamsters, gerbils, and ASFs. Best thing for you to do at this point is try another hamster.

If he is losing a lot of weight, it may be time to take him to a vet. A snake that is refusing food but not losing a substantial amount of weight will be fine, but losing too much and there might be a medical issue. Try the hamster again and if he refuses it but is getting pretty skinny, a vet visit never hurts anything.