No parts for a Toyota Supra

Whenever we order a part for a Toyota Supra there is always a wait of more than 4 weeks....Does Toyota Sa not keep any parts for this vehicle? I have logged a call with customer service....I have been told there is no time frame when the part with arrive in Sa....Why does Toyota sell vehicles without keeping spare parts? The after service regarding parts is unacceptable. All customer should be advised regarding this matter before they purchase a Supra