A garage company literally teased me.

A garage company literally teased me. I’m not usually one to care about stuff like this but the unprofessionalism was off the scale, My car has a leak from the coolant.. long story short i dropped my car off early morning and got a call back from the garage the man stated they couldn’t find any leaks etc. I was talking on the phone asking when i could pick the car back up etc obviously the best i could, The man on the phone i assume a mechanic or etc literally repeated my stutter back to me and mocked it. I am not really sure how to feel about this? I have never experienced this with an actual company or in any professional setting. What would you guys do?