Refusing to help Customers

My parent got a 50 dollar tip,that was by accedint washed, from a client.After Fnb confirmed that its not **** they wanted a pasport,since they dont have a pasport,i went to American Express Wonder Park.

When a got there the lady (top deck tabel top) was rude,she then said with sarcasm the note is ****,there is no strip, went to the fnb there and then back to American express.I said to the lady that 2 banks confirms its not ****,so she clicked her tongue and started talking to her collegue next to her in her languge.

I asked for the manager,he came and inspected the note,saw the silver strip.He confirmed that the note is not ****,sevral times you can see its legit,but he doesnt want to exchange it. Hes scared.

How in the world do you let people like that work with customers.