It depends on your relationship with the company. If you have a contract for a specified amount of time, then yes, they can refuse you. Read your contract, if you have a copy (you should). It definitly should have a clause that you or the employer may terminate the contract at any time for any reason. It’s pretty standard in most contracts, if memory serves. If it does, then their letter means nothing. If it doesn’t, though, then you may have a problem. In that case, they may be able to reject it. You’d have to get a lawyer’s opinion at that point (or someone more schooled in law then me), because there may be (and hopefully is) something on the books that says that an employer can’t force you to work, but I don’t know. Good luck!