Forcing to get my bank account number for security

I phoned in to Vodacom and supervisor Shelley Brown wants my banking account number, for security purposes. I tried to explain to her that I am currently working in the field and are far from home, cant give her any info on what contracts I have because my wife does not know what I'm doing with my documents, and doesn't even try and look for an alternative solution to solve the problem. So I'm going to cancel my contracts with Vodacom, because their services is ****!!! ***