Application declined for no reason

I went into my local Game store to open an account, because I seemed to qualify for all the criteria specified only to be told I am declined because no credit is available. What does that even mean? They asked me if I had any other accounts, which I had a Mr price account which was paid up this year along with a credit card that was also paid up. Nobody checked a payslip or bank statement just immediate decline. Phoned the number provided and the consultant also couldn't give me feedback.