Very frustrated

msslickster1

I purchased a 2011 Buick Enclave from a used car dealership in November 2017. Since Jan I have been having intermittent issues with the vehicle not starting, or once I turn it off it won' start back up. One mechanic replaced the fuse box which costed me $500. After getting my vehicle out of the shop it did not start the very next day. 3 days later I had it towed to a Buick dealership and the only thing they found was I needed a battery which costed me $250. I have an extended warranty but none of this is covered under the warranty. It did not start two days after replacing the battery. I took it back to the dealership and they kept it for a week but the problem never duplicated itself. I have had the car less than 6 months and no one can seem to figure out the issue. I also experience issues with the radio, brake assist, traction control, check engine light etc.when my car is about to give me problems. I don' know what to do. The dealership I purchased it from wants me to bring it back and they will try to diagnose it again. I just want it fixed or a different vehicle. Can somebody help me if they experienced these issues?