Discount Tire review: oil change and filter

Yesterday, my wife call the store in 836 W 6th, Corona, Ca 92882 and checked the cost for out Toyota Sienna synthetic oil change. I believe the mechanic there has enough knowledge to know about this popular Van and provided estimate of $54. This morning, my wife bought the van to the store and a mechanic got the key and checked the mileage, and again, for sure the mechanic knows exactly what the size of the Van and estimate $60 for the oil change. However, when the service was done, the store charged for $84 with a reason of needing more oil for the Van. This is totally a dishhonest transition to charge more to a woman customer.
not only that, the mechanic also tried to make a sale on site to my wife for replacing filter for $30, then ended up charged $60 2 engine and air filters (I have no idea what's the engine filter.
I don't understand why Discount Tire allows mechanics to scam woman knows nothing about car for money. The truth is they can make $50 or more one time, but they will lose the customer for life. if they don't straight this thing out, we who own 3 cars never have our car for their service again in the future and think about how much money they will make from service of our cars