Over charged for tire change

We were traveling home on Labor Day when the tire blew out on our car kaddy. We immedialtely called roadside and they connected us with someone that didn't even know the area we were in, he told my hubby he would have to find a place opened and that had a tire and would get back to us asap. Well, 2 hours later we heard back from him but told him not to bother because my husband had taken the car and gone to Walmart which was just off the interstate where we were and got a tire, put it on and we were on the road again. The guy said it would cost us $320. Hubby goin to Walmart it only cost $130 and a few headaches. Really am going to have to re-think if I want to spend the money on this again. Very, Very disappointed.