I sorry about the problem here, I am not sure why we would of suggested you use a 4S lipo with the ZMR 250 when the ESC labels say 2-3s on them! but to be fair we do deal with so many quads sometimes we can get abix mixed up, especially when replying to emails late at night!
So I hare just replied to your email you send us with return details, but I suggest you return all the stuff you got from us and myself or Sam will check your ZMR250 and repair anything that has been damaged by over voltage and we will also refund the 4S lipo if you no longer need it. We will then return a fully working zmr 250 quad back to you
Also it might be best if you can also return your radio control gear so we can bind it to your quad so it will be 100% ready to fly when you get it back.