Beverly Tire

I purchased WagJag oil change coupons for Beverly Auto & Tire (I previously got my oil changed at my local garage) for both of my cars (2004 Intrepid & Echo). After the first oil change I experienced "leaking" problems on both cars, previous to this I had no problems with my cars, I take very good care of them. I took the cars to my regular garage to find out what was causing the leaks. The Echo had to have the transmission replaced ($2K) and the Intrepid is still leaking oil, I have to take it back to my garage to find out what's going on. This is the first time dealing with Beverly auto & tire so I don't know what to expect, but what I do know is that there was no problems with my cars before I took them in for the oil change and I had problems after the oil change that has ended up costing me a lot of money. I would like to know if others have had an experience like this, is the WagJag coupon a way to get cutomers in the door then "create" problems to get return business... I'm really pissed!