Please advise me about returning an expensive item and canceling the check.

I don’t know your local laws, but if you actually return it, and don’t rely on them to pick it up, you should be OK. We used a credit card and bought a spa from Cal Spas (Just drove buy and they are now out of business YEAH! )
When we got it we realized that the box with the computer in it had been opened and parts raided. They wanted us to wait for parts.
We had to put the spa on a truck and return it. I took pictures of us returning it and left it in front of their door. The credit card company sided with us and gave us full credit back. (NEVER BUY A CAL SPA!)
The check might be harder, but if you cancel it and return the furniture you should be OK. Some states have a “cooling off” law that allows you to get out of a contract after you go home and change your mind. Good luck!!

Hurry and return it within three days and you should have no problem.