I don't usually coddle people so with that disclaimer. ..
You need to get your snake back and then call animal control on them. YOU are just as irresponsible as they are if you don't report them.
You're overthinking this. Your snake will be just fine without heat and such for a couple weeks. Get it back NOW and stop the excuses. If you are so broke that you can't spend $15-20 on a tank, rehome your snake to someone who can. I assume you can feed your mammals, so I don't buy that you cant find the money to care for your snake. If you seriously can't, find it a new home.
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