Automatic Transmission Center

I have been to this mechanic over the past 2, almost 3 years.  Finally realizing that they may have cost me money instead of saving me money.  I initially went for an engine light.  They diagnosed it as CATALYTIC CONVERTER. My car was in shop for 2-3 days.  Not only did they say one of the catalytic converters CRACKED during the repair and needed to be welded while they fixed it, but the engine light was off for ONLY ONE DAY.  Came right back on after I spent $800.  Since that day, I have been back to replace the IONIC motor, power steering pump, a FULL TUNE UP that they claimed would fix the engine light.  They always said that the TRANSMISSION was fine no matter how many times I reported a problem with it slipping or my car just completely turning off.  I spent so much money there and I STILL have an ENGINE light on.  Finally, took it to another mechanic someone recommended and he reported that they used CHEAP parts for the catalytic converters, didn't replace the sensors when they did the original work, and NOW the whole TRANSMISSION is messed up because it has been LEAKING.  I BEEN SAYING TO CHECK THE TRANSMISSION and they never did!  Isn't that supposed to be their speciality? Now I will have to pay $2500 to fix my entire car. NO THANKS TO AUTOMATIC TRANSMISSION CENTER.