it's only right that they charge for the parking at City Center. Prior to that new rule, you could hardly find a parking space because majority of the parked cars were from those people working near the mall and also those people who are just there to pick up passengers (private taxis). It's for the convenience of the customers really. besides, if you're not happy with their rules, there are still other malls in Qatar which gives free parking space, Villagio and Landmark to name some.