very bad experience with this case

very bad experience with this case
i needed brake discs and pads for my leon cupra
I call ahead for a price
they ask for my chassis numbers and license plate so that they can see what is on the car from the factory
they say 960 euros and 60 euros for the replacement car
I then bring in my car
once I got home with the replacement car, I get a phone back
with the story and I quote ff the seller ruben that I had on the line "the mechanic was wrong, the price is 1720 euros" it was nevertheless ruben that I had on the line for the price in advance, not a mechanic
i direct from wtf! no i will not do that, i cannot afford that
I immediately return the replacement car and the seller ruben cancels my repair free of charge.
he also says that I can also do it cheaper by just assembling everything myself, the cost would then be 1398.97 euros, I think ok and he gives me a copy of the order form only the front so
I had signed that he would call me when the parts were in the next day
the next day i was driving when my car suddenly made a lot of noise while driving and braking there appeared to be a lot of friction between my pads and discs when driving.
out of necessity we went to another garage of seat to have our car made.
I explain the situation on the phone but I am immediately told that I have to pay because I have signed the order form
I only have a copy of that order form that Ruben gave me when I returned the replacement car
I was therefore not aware of the sales policy on the back of such an order form
now I am allowed to pay them 30 percent of the bill, 413 euros
i got their invoice by mail 7 days later then finally their policy was on the back
states that you can prove another case of force majeure by registered letter
I did that immediately and included a copy of my invoice from the other garage
here they have flatly ignored me even after another telephone contact with the manager end of story you have to pay sir
bad service I call that I will never come here again