Note: I'm not affiliated with the project directly, nor I'm team member. I have been hired by Jumbo Ticket to post this ANN thread only. though you clearly mention this here mate yet I think they offered a great bonus of 50$ that can be used for ticket and withdrawable if ever wins.
maybe tomorrow night as my gambling day? will try to visit your site and take that bonus out lol.
Getting back to the issue- Phone Number
I believe Jumbo Ticket should consider this. There are more ways to prevent abuse of the bonus. But most users here don't like to get KYCed.
Though most of us hate KYC yet if this will be the safest way to gamble and with Phone verification only i believe that this can be given as there are multiple availability of Phone number from place.