Extremely poor service from discovery

Terrible service from discovery asked them to upgrade my car rental to an automatic. I also asked them to calculate the difference as I would pay it, the calculations were incorrect. Avis wanted 3k upfront which is not what discovery told me. None of my instructions were followed. Avis dropped off a manual vehicle. I haven’t driven a manual in 4 years. I called them two days before I dropped my vehicle with panel beaters.