Reliance Home Comfort

I contacted Reliance on Sunday evening to say we had no hot water - my 90 year old aunt and I. Service set up for next day 1-5. Technician came around 10 am. working on unit for about an hour - could not fix it needed two parts. told me to call Reliance to see if parts were available. They were not and there was no evidence they were ordered. It is impossible for me to go over the journey of trying to get this unit fixed (which has had many service calls) or replaced. I made way too many calls, spoke to too many people and spent hours on hold only to be told how sorry they were and how that should not have happened and so on. It's Wednesday night and we still have no hot water and no appointment scheduled to repair or replace this unit. The last person I spoke with still said it looked like the parts weren't ordered but I should hear within 24 hrs. I don't know what to do - this is the absolute worst service I have ever experienced. Sears transferred our account to Reliance for rental of the water heater - given the option I would not use this company or recommend them.