*****ed up Billing from Vodacom

I ask for a 24 month contract to be cancelled on the last month of the contract and was told it had to be done on the last month prior, no problem, I did so after given some run around and eventually got that done. On month 23 I was charged less and on month 24 I was charged more, not only did it make up for the previous month but an extra R20, The call centre could not help me after spending 30 minutes on the phone. Vodacom your billing system is *****ed up -really sad for an organization of your size!