Air Conditioner problems of the 2015 Buick Enclave

Air conditioning just stopped working. My 2015 Buick Enclave just turned 30,000 miles. Imagine my shock when I was told it would cost $1,530. 83 to repair. Warranty appears to be 3 years -30,000 miles. I've noticed a lot of complaints on line regarding air conditioning problems in this make and model and wondered if a recall had taken place. I've been a general motors gal through most of my life. My father started at a �repo man with gmac and retired as sales manager 1970. I was secretary to branch manager @ motors insurance company in my younger days. A lot of trust and loyalty to gm over the years, when I became a widow and needed to buy a car on my own, I was excited to go higher-end and purchase my Buick Enclave, thinking it would last for years. Then in June 2018 transmission or drive train failed but it was under warranty. Then in July 2020 during a routine oil change I had to pay $222. 14 additional work. Was told by local mechanic that none of this was needed. Bottom line, I spent $50,000 to purchase this vehicle and now I certainly do not feel secure driving this car. Living alone requires reliable transportation! hope you will find a solution to help me with this huge ac expense. Apparently the diagnostic test preliminarily cost $200. 00 alone. Which is crazy. Thank you in advance for your kind consideration. Dealer is I. G. Burton, 17861 coastal hwy, lewes, delaware 19958.