Contract considered invalid after approval

I've been discriminated upon, I went to apply at beares vosloorus, my credit was approved, chose what i wanted, provided them all the documents, I even signed the contract and was told my staff would be delivered in two to three days , however today I have been told that they will mo longer be providing me with what I want because I am not a citizen, I am a permanent residence, my parents are born here in SA, im being told to bring a passport and and 20 percent deposit. How can this be when I've signed everything required , this is the first time I have heard of such a thing, I grew up in this country and I pay my taxes, I have other accounts which I've never experienced such nonsense, I wasted my time for nothing. I'm very disappointed and I feel discriminated upon like a dog just because of my citizen status.