This is why you never do a Land Contract. Also, while we're here, never buy a house with someone you're not married to.

why is verbal in quotation marks? Does that mean there is a written contract/lease somewhere?

ok this needs some clarification cause the verbal part is in parentheses. makes it seem like it wasn't just a verbal agreement

If 10 years ago you were old enough to have your own money and pay rent, that means your grandpa is quite old. Possibly not too bright any more, memory failing (like remembers his childhood, but not the contract), add some outside influence, whatever, a cousin who wants the property or overambitious new lawyer, and here you get the picture. See what can be done, maybe he needs legal guardian.

If you got a letter from an attorney, then you've got acknowledgement of the agreement. You may have some legal legs to stand on in regards to maintaining your 10 year lease, or a refund (or partial refund) of your rent paid.

"Family" or not, take him to court.

Sounds like its time to cash in on grandpa. XD

FYI OP! I'm sorry you have an asshole Grandfather. My husband and I had a similar experience when we signed a written contract to take over my in-law's business. We moved across the country and after the first season they decide "we're going to just sell the business". Took it right from us. A couple of months later they served us with a letter threatening to evict us from the rental home, so we packed up immediately and moved back to my home state and my husband didn't speak to his mother for 3 years. We had a baby under 2 and I was 8.5 months pregnant when we moved. We could've sued since we had a legal written contract but we didn't. I'm not sure why; I suppose we are NOT asshole family members. Good luck to you.

Been there before...dont rent from family, business is business. Learn the lesson and move on. P.S. this is a lesson from your grandpa, hug him and be thankful...go find another house and stay in the will.