Fast-Fix Watch Repair - Worst Battery Replacement Experience

I am very disappointed at the Fast-Fix store located in Arcadia, California (Westfield Plaza, Santa Anita Mall). Over the weekend, I brought my watch over for a battery replacement. They first told me that it would be around $10, but when they see that I have a Gucci watch, the price became $20 plus tax. I was fine with that, since Gucci is an expensive watch. I was told to come back 10 minutes later. So I went back there in 15 minutes. It took them forever to look for my watch. Ok, they finally found my watch and informed me that my watch needs repair. They said they replaced the battery, but my watch is still not working, and therefore needs repair. My watch was handed back to me dirty and filthy. They asked for $55 to do the repair. I asked for a refund because I did not believe them since my battery died for only a week, so I brought it to a different place. The tech there told me that somebody had previously tried to unscrew my watch, and messed up my screw, because they were unable to unscrew it. To make a long story short, the tech at the other place replaced my battery and cleaned my watch for me at a very low and reasonable price. To me, if you cannot do the work, tell me you cannot do it and do not charge me $55, ruining the screw of the back of my watch, and tell me that the inside of my watch needs a repair. How can businesses be so dishonest nowadays?