Bumper to Bumper Auto Parts

Our vehicle has been in their repair shop 3 months within the past 6 months and it is still undriveable. We had the engine replaced twice and spent 6k
Our black mercedes has been in and out of bumper to bumper's repair shop several times over the past 6 months and we have incurred 6k in repair costs. Every time they say the vehicle is fixed, we pick it up and it breaks down within a week or two that we got it back. One time, when it broke down in the middle lane of a highway, the tow truck driver showed me antifreeze spewing out of a hose that was not even connected. On 2 different occassions, Jiffy Lube has refused to change the oil as it is extremely dangerous to drive with oil spewing out. Bumper to bumper replaced the entire engine twice. My safety with my special needs daughter has been compromised on several occasions due to the ineptness of this repair shop.
The initiial engine replacement was guaranteed, and we have been trying to get our money back to purchase a safe vehicle. Each time they wind up charging us more money for a vehicle that is not repaired and driveable.