Upgrade declined.

I have been a client of vodacom since I can remember! About a year ago I had and outstanding account due to unforseen circumstances and made arangements for payments. The next moment my phone and ipad accounts has been deactivated despite of the arrangements made and i had to pay a large amount and buy new sim cards etc. I waited a few days before my phone was activated again. Then oneday someone from vodacom contacted me and told me that I qualify for 2 gig data for my tablet at a discounted price of R109 per month. Now all of a suddon I am unable to upgrade my ipad because apparently that discount was an upgrade without a divice wich I was never informed about. The person said it is a line upgrade from 1 gig to 2 gig and said nothing about the divice!!! Now my iphone is due for an upgrade but apparently because of the payment issue which I made arrangements for more than a year ago, I am unable to upgrade!!! I really think this is unfair and deceiving because i've been a client for so long and the one and only time i made arangements to pay they do this???