Cancellation horro

Been trying to cancel my sim data contract for 2 months now. Called yesterday and was advised that my debit is in arrears so they cannot cancel until I pay and I told them that they had just debited me earlier in the day The advisor then told me it will only reflect the following day and I can then call to cancel as they will he open from 9 till 2. Then I call today and I am told the cancellation department is closed!!!! I work at a call center myself and believe you me I am the most understanding person as I also understand the environment but this is inadequate service, I mean I dont have time firstly to be holding for an agent to be available let alone to be given the run around when I just want to cancel their data that doesn't even last for 15 days yet half of my day I'm not even on my phone as I'm at work. May you please action my cancellation