Confused about their vetting

I'm thwarted by the mtn vetting department. I app**** for a new contract and was declined. I earn more than R4500 a month, permanently employed and have credit history. I had a R400 contract with another provider but mtn declined me for R199 which is half of what I've been paying. Funny enough I'm good for R250000 credit from my bank but not mtn. I was looking forward to experience their service but they don't even what this unmet criteria is. This is a sure fire way to prevent them from getting new business and expanding their client base.