There's your problem right there... you don't know what the temperatures really are. From the sound of it, they're too high.

Even with a thermostat, and it's great that you have one, you won't have the right temps unless you have the right thermometer or a temp gun to measure them. BP temps are important right at floor level, not halfway up the enclosure.
Not trying to flame you for having those crappy dial round things, since pet stores hardly ever give proper advice, but just trying to let you know what you need to keep the cage going.

Dial the thermostat down until touching the glass brings a strong warmth, not high heat. Do that for now until you can get proper thermometers. Your snake should be fine with slightly lower temps until you can sort things out.
And there is often a degree difference between what the t-stat says and what the actual temp at the inside floor is, so you can't trust the thermostat reading to be the actual temp inside.