Firestone Complete Auto Care review: Tire mounting

I had 4 new tires put on my car a couple months ago. I kept what they said was the best of the four (I had some doubts as I saw the person grab up the first one from the stack with no real scrutiny on any, but as he had changed them took it as he saw them all as they were being changed out) and was told by the manager that day that once I found a new rim I could have it mounted. Finally got it in and able to take the new rim and the tire back to have mounted. The manager on duty said they couldn't mount used tires as it was a liability. Then said if it was one of theirs maybe could and he looked at it. As it was a Cooper tire he said no, and then told me the tire was bad anyway. (They had all passed inspection a couple weeks prior to changing, btw, was showing wear though, not unusable though) He was more than willing to sell me a new one though. I can see even though this location was an Expert Tire prior to the rebranding, they still run shady deals and lie a lot; anything to make a sale. I like Firestone tires, understand that policies may have changed in the years since I worked for Firestone, but I DO N0T appreciate being lied to and tried to get jerked around.