Honest 1 Auto Care Charged "Diagnostic fee" of over $100 and didn't diagnose anything.. Deltona Florida

I was charged a "diagnostic fee" for the "mechanic" to basically tell me what Autozone does it for free and NOT ADDRESS THE ISSUE!  They kept the car for over 24 hours, to give me a diagnostic of "catalitc converter" something it has been known for years and tried to charge $1100 for the repair that wouldn't have fixed the original issue mind you. Tried to ask why and to reason with the person, but I was literally charged $100 with tax for someone to stick a $12 diagnostic tool on the car (on amazon you can find it) and tell me what we already knew. Awful and will absolutely never come back. In addition, we had another mechanic do an inspection just 30 days back, we have several issues that needed to be handled and their "diagnostic" missed EVERY OTHER ISSUE the car had. The only thing that was done in a 24 hours period was checking the engine light.  Utterly ridiculous and a ripoff of giant magnitude.