Bad Credit Vetting

I recwntly app**** for a new cellphone contract at telkom only to be declined flat out, I don't have a bad credit rating my name I's completely clean but somehow I am being declined and they refuse to give answers as to why, they won't even tell me how we are rated as to what are the criteria for passing the credit vetting, in store if you fail it they require a deposit of R750 up front, to me this just seems like a **** to get us in store and to pay them that extra R750. It just feels like some kind of a bribe to be honest. For such a big and popular company Im really shocked & disappointed that their performance regarding this is so pathetic