This answer, or something extremely similar, has already been asked before, at MacBook Pro locked with Find My Mac and won't let me boot. That said, this question is not a duplicate, as I need an answer not listed there. One of the solutions was holdign down command-option-P-R as the computer turned on. This does not work for me, even though it should. Apple support has said I would need to come in to a store, but as it's a long drive, I would prefer to find an answer that does not require me to drive there. If nobody can answer this, please tell me what they would do at the Apple store, if you know.
What they would do in the store is work with you to make sure you don't really have access to the Apple ID. They would also seek to identify you as the original purchaser - if you can provide proof of identity and proof of purchase, they might have a procedure to erase the lock.
I would work with AppleCare on the phone or internet to see if they can help with the Apple ID. Then you can decide to drive in person to Apple or perhaps see if there is a closer Apple Technician that could assist you with an unlock. The benefit of Apple is they don't charge money for this service - and you might pay someone else to assist.