Bad service

We decided on a vehicle with we buy cars South Gate.. Went for a test drive. Look at the dekra report. Which was great.. On the day of delivery the front window was cracked quite bad. .. Why was we not informed that something happened to the window before we took delivery? We had it repaired but is losing our no claim bonus.. We paid for a extended two year warranty.. On the warranty the year model of the car is not the same as the contract as, well as our physical address. And we buy cars don't come to the party at all.. You are only a important to them for the deal.. No After sales service at all