Firestone Complete Auto Care review: Tires

Good afternoon,
This the second time this has happened to me at this Firestone in Tyler Texas. Before coming to fire stone I purchased 2 good used tires to get me through for a 1999 Honda Accord. I then bought 4 Tires from firestone and asked that the old tires be put in my trunk/car so I could use for spare just in case ever needed. (NEVER HAPPEED) Recently I was loaned 2 GOOD Front tires for a 2004 GMC 285/45R22 to get me to Firestone to buy 4 new tires. I informed Johnathan 3 times to put old tires on back of the truck 3-TIMES I informed him. When I picked up the vehicle NO TIRES. Now I have to replace the guy tires and was offered 30 Dollars on the purchase of 2 used tires. Where can I find 2 good used 22 inch tires for 30 Dollars. The Customer service here SUCKS! Its the only Firestone here in Tyler and I needed to use my Firestone card because times are hard lately. I need firestone to replace those 2 tires.