I just had my car serviced here for the 75,000 mil...

I just had my car serviced here for the 75,000 miles maintenance for my XC90 V6 2005. I called several shops to get a quote for the maintenance, believe it or not Carlson Volvo in Palo Alto was cheaper so, I took my car there. But here is the catch, I then received a call from the service department and they told me that the car needs a repair for several things. I don't know anything much about car so I said OK, well I end up paying 4 times the amount of the original price, I end up paying $1,800.00. I'm so unhappy about it, this thing happened to me before (same thing, cheap when for quoting but somehow, once checked there's always something wrong with the car, or some repairs needed that doubles or triples the amount of the original quote. I seldom drive my car, I don't even put 800 miles a year. I asked if all the repairs are necessary and of course they said yes. Sigh.