I paid in full for a tombstone for my Dad back in March. The owner went through some complications and as of yesterday (September) I called it still isn't done yet (no time frame listed on contract) and he couldn't even locate the invoice to reference the sale. What is my course of action , I live in Massachusetts. Thanks.
Send a demand letter complying with MGL Chapter 93A - The consumer protection statute. Give him a specific date to perform by. If he does not perform by that date, you can take him to court (Probably small claims - it has a $7,000 limit), and sue him.
Chapter 93A provides for legal fees, so you may want to find an attorney to take the case.
Check the Attorney General's website for a sample 93A demand letter. If you don't do it properly, you may end up waiving some rights.