The marketplace eventually takes care of stores like this. There are several chain-type tire stores in my area that I will not patronize becasue of similar treatment.
I buy tires from a non chain store that has suceeded in business by satisfying local customers. Satisfaction and word of mouth is a good combunation.

Before I found the non chain store, i bought a set of tires from Pep Boys, at a very good sale price ( They are always "on sale"). Later I had a pro rata adjustment to a covered defect--but the adjustment is always pro rated against the mythical "list" price, causing a warrantee adjustment to cost more than a new tire on sale. Last time I bought tires from the Pep Boys; never again.