Firestone Attempted to charge me 3400 for a "blown head gasket", gasket was not actually blown. houston Texas

In mid-November my partner took his vehicle (2007 Chrysler 300) to a local Firestone, because it was having trouble starting. The engine just wouldn't turn over and Firestone was very close to his apartment complex. Fast foward a few hours after taking it in to see what was wrong and Firestone says that the head gasket is blown and that there is severe engine damage and quoted us 3400 for the fix.  At the time we were freaking out, because that's an expensive fix! So we take the car to his apartment and decide what to do. (Side note they also broke the oil dipstick in his car during this process, didn't say anything, and tried to blame it on us when we asked if they could replace it).

We wait about two months before coming to a decision so we could save the money to fix the car. Instead of taking it back to Firestone we take it to a more locally owned shop down the road. The local shop calls a day later and says the gasket was never blown, there's no engine damage, and that the cooling system just needed replacing (a 235$ fix). The two month wait severely set us back, as we thought the car was almost unusable and had to use other means of transportation. I don't usually get riled up when someone tries to rip me off, because it happens so often in Houston, but this is absolutely terrible. Not having a car in Houston, Texas is something that can cause you to lose your job! It's tragic to think they have done this to other people and gotten away with it especially over large sums of money.