adviced to pay more than I budgeted for

On the 4th of December 2015 between 13h30 and 14h00 I went to Vodacom store to try to get my two kids tables. I spoke to the Ndumiso who did all the necessary documents and faxed it. He told me it takes 3 hours max to get feedback. I then called in on Monday 7th and was told that Ndumiso is off sick and my application is approved, I decided to go into the store. I got there and a lady helped but she couldn't do more because she couldn't find my paperwork and no one knew where it was. I then went back to my office, the next day Tuesday 8th I called Ndumiso who told me my contract was approved but NOT for R69 Data Contract due to my low credit score but for R150 airtime contract. Which means instead of paying less I am pushed to pay more. How can Vodacom say my credit score is low for a cheaper contract but they expect me to pay double what I have budgeted for?