BMW the glen is a scam

I took my car in at BMW Auto glen for a diagnosis in mid-December the lady who we had spoken to on the phone confirmed our appointment but when we got there they refused to take in the car until we asked for the service manager who then agreed to take it in Long story short they advised that the diagnosis could take 2 days and we had no issue but after a few hours we received a call saying the whole engine needs to be replaced and it will cost 200k so basically no tests were run and they just wanted to get rid of the car so I had to pay diagnosis fees if about 2k. I couldn't understand how the whole engine could be faulty and we requested more information but nobody attended to us. We parked the car and finally decided to get a second opinion only to find that the clutch needed to be replaced and the engine is 100%. BMW the glen is unprofessional and I would never recommend it to anyone and I demand the diagnosis money that I paid as its clear that they dud not diagnose the car instead they gave us a ****py just so that they could enjoy their December holidays! Please refund me my money and take note that you've lost me as your client it drives me more mad that I was considering buying another car but I will never set foot at any BMW dealership