OP, do you have an old electric bill with you? Or maybe just a photo of one bill in your phone? If so, you can send it to anyone you know in Thailand (friend, gf...) and they can go scan the barcode from the photo at 7/11 to pay for you.
Heck, if it's really 50 baht I'm even willing to do it for you ????
If not, call the juristic office of your building and ask if they can check for you if you have unpaid bills (they should manage to find out). I'm sure a solution will be worked out then.
Also, the PEA company will not cut your electric meter for 1 month. They do it at 3 months currently and never did it below 2 months.