Worst service all over ! Misleading offers.

Worst service ever, I rented a car online. When i picked the car up they didn't have one and substituted it with a similar car that was in a LOWER group than the original rental. Cant belief that they expected me to be happy with the rental offered I had to upgrade at my cost. Its 3 weeks later and my deposit is not refunded it took me two hours just to get hold of them. The email and online system is not working at all not to mention telephone just ringing