Upgrading

I have had my vodacom contract since 2012, and i have additional 2 vodacom contracts, i have always been a loyal member of vodacom. In september i called their call center to move my debit order date because my employer was going to process my salary at a later date than usual. The call center agent i was speaking to said it was successful from moving my debit order from the 3rd to the 7th of September. Whne the 3rd of September came, vodacom debited my account and the debit order bounced. Now that i am trying to upgrade one of my cintracts, they are telling me that i cannot upgrade becasue i am a bad payer, after i have made arrangemets for them to move my debit order and they failed to do so and now they have made me a bad payer on top of everything. I am highly disappointed in vodacom and i cant wait for all y contratcs to finish so i can do away with such bad service that have blacklistsed me for no reason.