Valvoline Instant Oil Change [VIOC]

I didn’t use this Valvoline Instant oil change here but I used the one in Madison WI, 3594 E Washington Ave Madison WI 53704. They replaced my transmission fluid on my 2003 Mercedes C230. One week later my transmission went out. I reviewed the fluid that Valvoline used “Maxlife automatic Transmission Fluid” and my Mercedes dealer said that this fluid is “Not to be used in my transmission the 722.6 type. The owner manual also states not to use the Maxlife fluid also. I contacted the local Valvoline Instant oil change [protected]) and they referred me to their insurance company.
After 1 month the insurance company refused my claim. They stated that they sent in the fluid (Maxlife and Mercedes fluids) to a Valvoline lab. They claim the Maxlife automatic transmission fluid is suitable for my now broken car. I have talked to 3 different Mercedes dealerships and each one knows about the exact same issue with Valvoline. I have presented Valvoline with all the documentation and they still refuse to correct the problems that they have caused.
Valvoline will not stand behind their work. I will never use Valvoline in any of my vehicles and recommend no one else does either. Their mistake is going to cost me over $6000. This is the last time I will trust Valvoline.