Mavis Discount Tire

We bought tires from Mavis yesterday and they installed them for us.
They stained my car from the inside, on both sides, as if they stained the interior with greasy oil on BOTH SIDES.
When I showed them, the manager said that it was nothing to worry about, you need to be positive, and with his dirty rag he wiped the inside of the interior, leaving even more dirt inside.
He also lied that they did not open the door on the passenger side, although I have a recording on the camera that they opened and sat in the front passenger seat because they were looking for the keys there.

The manager says what can I do, go to the detail center and wash it, why should I wash the car at my own expense when they dirty it and don’t admit it and also lie that it wasn’t them who dirty it.
I bought tires and expect that Mavis auto cares about their customers, but the manager does not even care about what they did.
That is the address where I bought my tires yesterday - 401 W Butler Ave, Chalfont, PA 18914.
My phone number [protected]