Jet application declined cos ID number is not accepted

So I went to Jet At Cresta as I wanted to open an account. the ladies that helped were good and friendly. but the guy was of no help. so apparently my ID number did not want to go through on their system.... I was rudely said to get a letter from the home affairs! what letter don't know. I had no problem opening my other accounts (Truworths, YDE) I thought that new business would be very important to a retail store, but apparently not for Jet. so maybe I'm born in 2000 and that had something to do with their system. but I was just sent away.... so how do I get a Jet account???