Other Fuel System Pump problems of the 2015 GMC Acadia

While driving in heavy city traffic, my warning lights came on for "reduced power", 'traction control" malfunction, 'stabilitrac and abs lights came on. Power reduced to 25mph. I was close to the dealership and went there right away. The service writer told me I would have to wait at least 2 to 4 hrs before anyone could look at. My mileage was 36,432. . . 432 miles out of bumper to bumper warranty. . . He told me the charges for diagnosing would be $130. I agreed. Then he explained that the the low hp fuel pressure/purge solenoid was stuck open, dianose codes were po191 and po496, they replaced a high pressre fuel pump, r&r intake plenum to replace fuel rail pressure sensor and replace a purge control solenoid. Cost to me was $1,760. 51 ($866. 06 labor- $820. 43 parts -$30. 00 misc. Charge-$82. 29 misc. Discount- taxes of $126. 31. I don't understand why they couldn't be more lenient with mileage on warranty. I purchased this vehicle new from them and have completed all my service work there. This was a scary situation in noon rush hour traffic without any roadside pull off at the time. Could there have been a defection fuel pump? I was told by service writer "if you had driven any further more damage would have happened to engine block".