First of all RELAX. I know its a crappy situation but you just have to realize that the law is the law and for the time being its not going to change and there is nothing you can do about it.

Now Like others said check to make sure it is the law and its current. If it is and you are in fact not allowed to keep ball pythons then its up to you whether to rehome the snake or not.

Most importantly whoever this pet store is i would steer clear of going there or buying anything from them. They are obviously very mis-informed on herping.

Other than that I am sorry about your situation and wish you the best.