I sent 50.00 to someone that disappeared. Any way to report the phone number of scammers??

You will not be able to get your money back. Apple recommends to never send money to people you don't know. That is a private transaction between 2 people that does not have the protections like you would find with a credit card. It would be the same as giving someone $50 on the street. Nobody is going to give you the money unless the person who you gave it to gives it back. Apple details sending Apple Cash here:

Apple Cash person-to-person payments are like any other private transaction between two people, so only send and receive money with people you know. 

Send and receive money with Apple Cash - Apple Support