CELL C/Hollard mobile insurance ****

I cancelled my insurance on the mobile 07Oct 2022. And was informed by email and text that the cover has ceased with immediate effect "their words..from this moment. 31Oct debited with the full amount for the insurance. Contact with the service centre ignores the letter and the text and informs me that there is a months notice thus the debit. Challenged with the fact that all insurance is debited in advance they continued with their stance..in fact i think they don't even understand the fact. End result is they expect me to pay for the 3 weeks without any cover !! Client service ..hopeless, inarticulate and uninformed.