Titus-Will Chevrolet Buick (Chehalis)

I purchased my car at I-5 Toyota two years ago. It's a 2011 Chevy Travers. I've always had my maintenance done at Toyota with Fully synthetic oil (ALWAYS). I had a timing chain problem that was covered under warrantee so I had to bring it to Titus Will to have it repaired. They had my car for over 1 week for repairs on January 29th-February 6th 2015. During this time they said I needed my breaks done, was due for an oil change, and also serviced a recall. I went ahead and had all this service done. The recall and timing chain was paid by the warrantee and I paid for the oil change and breaks. Once I picked up my car I was hearing some vibrating noises and my automatic gear shifter was stuck in reverse. I had it towed back to Titus Will and they found NOTHING wrong with it. I have documentation that they said they found nothing wrong and drive and report!. On June 27th 2015 I was headed to a birthday party with all six of my kids, going 60MPH down the highway, my car just loses all power and I coast to the side of the road. I had it towed to Titus Will for evaluation. I'm still current under my power-train warrantee until October this year. I get a call on Monday saying my motor is completely done for. It seized up and I would need to have a new motor put in. The cost is $7,200....... and my warrantee would not cover it because I was low on oil which was the cause of my engine to seize. I asked how I was low on oil when they just changed my oil four months ago.?? "I was over due on my oil change by 2,000 miles and I burnt up all my oil" is a direct quote from them!!! My oil was changed four months ago almost to the date!!! I asked if I had any leaks because I didn't understand how a three year old cars motor blows with no warning. They said there wasn't any leaks at all. No oil light was on, no engine light was on, no black smoke was coming out of my car, no noise of a ticking engine!!! How is this possible I asked. They said I went over on my oil change and that's what caused my engine to fail. I find it hard to believe that just four months after they tore my entire engine apart, it BLOWS!!!??? They did nothing to help me and were not very nice to me while explaining it. I would never trust them to work on your car.