Mavis Discount Tire review: oil change

Had my oil changed on 7/25/19, the mechanic left off a seal and oil poured all over my engine and driveway, brought the car back for them to fix next day, manager claimed it was the seal. It's now 7/29/19 and my car is still dripping oil. Manager says they checked it and couldn't find any leaks and says its the left over oil from the leak. The car wasn't leaking when I brought it in. You would think mavis would clean my motor and find the leak but now they want to say it could have already been there or leaking from something else not the oil change they performed. I would like to talk with a mavis rep to help fix my issues.