Business ProfileforCadillac of Norwood

My car is making this weird noise so I brought to Cadillac. They said they were busy and offered to take me home and then pick me up when it was done. I took the day off from work. They called me and told me it was the flex pipe and it's broke and it will cost $1,700 to replace it. They gave me another option and that's to go to ***** exhaust and have them cut and weld it. It went to ***** in Stoughton they put it on the lift and said nothing is wrong with flex pipe and no leaks or anything so I got a second opinion and went to one in Brockton and they said the same and the guy said I don't want to take your money and nothing is wrong with flex pipe. I called Cadillac and told them and I said I paid $160 for the diagnosis and ***** exhaust said my flex pipe is fine and Cadillac said they had their best mechanic on the job and I dropped it off again and they had it all day again and I received a call from Cadillac and they said they it was definitely the flex pipe and all the mechanics could hear it and he sent me a photo of the part that was making the noise so I went back to ***** exhaust and showed them the photo and they said okay we will do the job so the replaced the part and he kept saying I don't think that's it and have been doing this for 22 years but I'll do it. They changed it and I drove off still hearing the sound and the guy at ***** got upset and said I told you! That's not what it was and I didn't want to take your money and find another mechanic or something. I called the Cadillac service manager and I left a message 3 times and I did not get a response at all. I am very upset. I spent $500 and I still have the noise and what if I paid the $1,700? They would had my money and still have the same problem. Please help me. Thank you!