Price Lock Billing

I subscribed to DStv Price lock plan last year October.At the end of the month i was billed for the entire 2 years contract . i contacted multi choice to make the aware of this billing error, at first i was advised that this would be sorted came following month my statement stated that i owed them the full amount still . i called again and was assured that this would be rectified . in January i again called 3 months later the issue was still unresolved . i have been calling since then last month after paying my subscription my services we suspended and i was told that the price lock account had been closed and moved onto my normal account and that i should pay it in 6 months which was not the contractual agreement between myself and multi choice . The reason why i went on price lock was to not incur increases for the next 2 years i have now forfeited that benefit and further more been inconvenienced into paying off the account in a shorter space , Whats more frustrating is for the past 3 weeks my account has been suspended 4 times and i have had to call in to reconnect . this is not just causing a financial strain by paying more than i anticipated but the airtime that i spend calling you each month and now weekly . i need this resolved urgently