Bidvest in Kolonnade Mall is robbing people foreign currency money

Yvonne Jacob's, at Bidvest Kolonnade Mall was the consultant . My friend went with 100dollar note and his intention was to exchange it for R currency. Consultant as per the name above took it from him and said its **** and she can't give it back to him. We didn't dispute that. I asked her to write ontop of the note that it's "****" and keep it because we not sure if she's telling the truth or not. My problem is that what if it's not **** and she keeps it for herself. She mentioned that it's the rule that if someone walks in with a **** note in the brunch, they keep it which she failed to show me that rule. I find it very unprofessional and I feel like they taking money from people. So we ended up leaving the brunch without her writing "****" on the note.