Debited my contract account late

Debited my contract account late. Then I was in arrears. Contract ended end of February went to Brits Telkom to cancel Contract. On computer screen it showed canceled no reference given. My number blocked couldn't use. Called telkom still blocked. Billed 650 . Called was told I didn't cancel the contract. Tried to cancel instead she want to tell me I didn't cancel.ask her to cancel still no cancelation. Now after contacting them on Twitter they cancel. *********** staff and ********** @Telkom.