Valvoline Instant Oil Change [VIOC] review: transmission

on 5/14/13 I took my 2000 GMC Yukon Denali in to get a routine oil change at which point they consulted the manufacturer's wanted and told me that there was a white substance bubbling on my transmission and I was well past overdue for this preventative maintenance. At their suggestion, I took this advice, it was the worst and most costly advice ever. On 5/20/13 my truck started to lose power as I had my foot to the gas petal, max speed was 40mph. I took my truck back to Valvoline. They checked my levels and said everything was ok. Well it is not OK, my truck now has a transmission that will have to be replaced. This is the worst feeling ever. The pit of my stomach hurts. The cost of the transmission is now the price of a new vehicle. I have contacted corporate with no response. Now I am on a mission to post this problem on every website possible. Before I went to this place, everything was fine. After leaving this place, I am in worse shape than I started. NEVER TAKE YOUR VEHICLE TO VALVOLINE. YOUR PROBLEMS WILL ONLY GET WORSE.