Call supposedly from Vodacom - possible *****

My brother received a call today from ***. He put her on speaker so I could hear. She was supposedly calling from Vodacom and asked if the number she called was his. She wanted to know who the account holder was and what their number was. Unsuspectingly he gave it to her not thinking anything of it. <br> <br> Something doesn't seem right at all. If she really was from Vodacom she would know who she was calling, who the account holder was and how to get hold of them. <br> <br> I was highly suspicious. Please can Vodacom confirm if this did originate from their offices?