Oil Change

I received a coupon in the mail for a $45 oil change. I booked an appointment for this service. Once, I arrived to the store with the coupon in hand and asked the associate if the coupon was valid for my service just to be sure of the cost prior to the service and was told yes. Once my car was done they told me my amount due was $150 for the oil change. I waited in store and no one told me the price change of the service. This was the worst customer service I’ve ever experienced.