Conning the elderly

A few months ago my 83 year old mother went to Vodacom as she had a problem with her cellphone. The problem was that she needed to enter a number in order for Whatapp to do a backup. The sales consultant convinced my mother that she actually needed a new phone and contract. He managed to get her to sign up for a 400min & 2GB contract when she very rarely made calls and a Huawei phone which no longer has access to google and she would never be able to use. She subsequently passed away and Vodacom will not entertain a reduction in this contract although I have agreed to pay for the device. Correspondence has been met with complete arrogance and phone calls have just been cut off. Vodacom is insistent that all future data and minutes shoud be paid for although they will never be used. Clearly this is an ********* Company and one that should not be dealt with.