2003 Volkswagen Passat Fuel Pump replacement

I have just visited that dealership and asked them if they checked fuel pressure, they said yes. I told them that it might be a bad check valve, they showed me that the fuel pressure (and residual pressure) is good. So they started to blame my starter, ignition, battery, battery cables. It looks like that the reason was a discharged battery, bit I am still not sure, because I made yesterday a 1 hour and a half trip and same this morning (I believe, but I might be wrong, it is enough time for the full battery charge) and still had this starting issue this morning. They charged me $750 for this supposed to be an 1 hour job and didn't even charge my battery if they are aware that the fuel pump failure can cause a battery drain (repetitive cranking, though I just attempted several time to start the engine).