High Mileage Oil Change

Usually, they provide great and fast service I have been going there for years, however, the last time I was there I was told there was an additional charge for a service (topping off my antifreeze) that is always provided with the cost of the high mileage oil change. Long story short, I left under the impression that all fluids had been topped off, and I was wrong the mechanic never told me he did not top off my antifreeze. About a month later I had a blown head gasket and, of course, it is my fault. I guess the sum of the story is be aware of all the fine print and services offered.