Dismal Service

Made a booking for a car yesterday specifically a polo tsi, called today om several occasions to reserve the vehicle but i was advised there is only one polo vivo in stock so when i go to collect the vehicle i see a polo tsi in one of the bay and i queried and apparently the vehicle is reserved kindly note that i am a paying customer as well how come some customers get preferential treatment as opposed to others i am paying for the rental and i deserve to drive what i am comfortable with. Kindly address this issue amd not i will not hire from Avis in the further, disappointmented seems the buy out off budget has affected service delivery.