Underhanded business prictice

After processing the cancellation of a data contract on 31 January 2022, I was shocked to see another debit order processed on my account on 1 March 2022. I gave clear instructions for this contract to be cancelled and my instruction was sent on 31 January which in any normal circumstance would constitute 1 months notice of termination of my contract with Cell C. I even got a phone call from a customer service consultant to process the cancellation in which it was agreed that termination would be at the end of February as expected. After contacting customer service on Wednesday to inquire why I had been charged for March I was told that may data bundle renewed on 1 March because my 30 day notice was on 31 January so the data automatically renewed, that extending my contract to the end of March, because 30 days had not yet passed (February being only a 28 day month)? I find this to be underhanded and ********* business practice! Not to mention that I asked the consultant I spoke to on Wednesday to get a manager to call me but I am still waiting!! I cannot believe they treat customers like this!! It is no longer about the mere R199, but the principal of the matter of deceit by Cell C.