Wrong device cancellation request

I app**** for an upgrade and of November. The new device that was delivered to my address was the incorrect device. It took MTN to arrange the collection with DVS more than a week to collect. Eventually is was collected on the 13/12/2022. I have been calling every day to confirm receipt of the device so the transaction can be cancelled as I don't want to be billed at the end of the month for a device I don't want. To date 24/12/2022 the cancellation still has not been processed. Very unhappy customer.