Chase Chevrolet

Went for an oil change and multi-point inspection. Got home, put the truck in the garage. Next morning, pulled the truck out of the garage, noticing a pool of oil under where the truck had been parked. I took the truck back to Chase. Seems they over-tightened the filter, causing it to leak. This is the second time this has happened. After replacing the filter and filling the oil, the mechanic said the oil drain plug was over-tightened and the copper washer was collapsed. Since they are the only ones that service the vehicle, they are the ones that crushed the copper washer on the drain plug. They said to remind them on the next service and they would replace it at no charge. My question is when they noticed it and it was on the rack, why didn’t they replace it then? Very poor customer service!