Vodacom sisappointment.

I am trying to cancel my Vodacom contract, since Sept 2022. I paid the outstanding amount, but when I e-mail the proof of payment, I receive an e-mail that authentication is required. When phoning the customer support, I do not get the opportunity to talk to an attendant, as I do not have the number of the device, which must be punched in first. This causes me to be unable to get the contract closed. I think that it is ridiculous that closing the account is made impossible, by not being able to forward a proof of payment or being able to talk to an operator.