I somehow have received 261 messages from a "mailing list"! It said ur phone has been hacked! how do I get rid of all of these? Help

These previous answers are both correct and just to be better safe than sorry if it were me I'd block the #, AND make an appointment to seek help from a customer service rep and/or a tech at the Genius Bar (@ your nearest Apple Store). Good luck and Goddess be with you!

Block the number

You need to talk to a apple care Rep to see what they can do for you