Contract application rejected

I was at Cell C store in centurion mall, I requested the requirement to apply for a contract phone, they told me recent payslip, Id, proof of residence, and 3 months bank statement. I went and get all these documents, I got back there are submitted it, the person attending to said he has to send the documents to there back office, he did and came back to me to tell me that they can only give the contract end of march, so why did they want 3months bank statement an when I got there they are talking 4th month. I feel this all because my id did not say sa citizen, so who ever was at the back office has no valid reason to reject the application as I have what they required. I have been using cell c now for about 2years and this is what I get.