What should I do after paying a fake registration fee?

Yesterday, I spoke to someone on WhatsApp who offered sex services through call and video call. I jokingly agreed, and they asked for my details, including photo, name, and date of birth. I provided incorrect information, but they asked for a registration fee of 499. I refused, but they insisted that police verification would be done and later told me my details were added, and I would need to pay the fee. I paid the 499, but now they are saying that the number I paid to was fake, and I need to pay again. What should I do? I am under 18 and cannot tell my family. Please help.