Firestone of Lisle

I had to drive a trailer loaded with kid's suitcase's from my church over 65 miles on the highway to a camp in Indiana, leave it there and pick it up the following Mon.
I brought my truck to Firestone of Lisle, Il on 2/11/2016 to have them check and repair the trailer connections and wiring on my Ford truck. I was told that they can do that. I told them to just replace everything.
When I picked up the truck they had spliced a new 3 pin connection to the old wiring and left it dangling (not secured to the truck). The other, round connection, was not replaced. They told me they cleaned it up and that it should work.
When I connected the trailer to the truck at about 4:00pm, the lights on the trailer did not work. I called Firestone and asked if I could bring it back and was told that there was no one available. I went to another place to try to get it fixed but they were closed by the time I got there at 5:00pm.
I had no choice but to drive the trailer with no brake, turn, etc. lights over 65 miles in the dark. The trailer was big enough to prevent anyone from seeing the lights on my truck.
I had to go pick up the trailer that Mon. and did not want to take another chance driving on the highway with no lights, so on Sun morning at 11:30 when I should have been serving at my church for services, I went to Farm and Fleet in Montgomery, IL and they replaced everything, mounted it correctly and made sure all the lights worked. I did not want to take a chance of another poor job from Firestone. Those lights are very, very important.
Firestone charged me $139 and did not repair the issues. Farm and Fleet charged my $60 and corrected all issues.
Firestone refuses to refund my money but instead want to issue me store credit. Why would I want to trust them to work on my truck again? 
On another occasion, they damaged my dash board. They didn't say anything and left it for me to find. They said they would clean it but when I went back, it was not cleaned, but I needed the truck so I agreed to bring it back another day. Once again, it was not fully repaired and I was told to bring it back another day. 
While discussing the trailer issues with a rep from Firestone, he implied that I was lying about everything.