Spam - 1 805 637 7243

I read their questions from three years ago, and everything has stayed the same. The numbers annoyed me. How can I stop them? 
It is okay to keep the same if they are spam or anything that annoys T-mobles customers? 
To T-mobles services - can you do something to stop and block the numbers for us? 

Also, the number is 1-303-810-8403, which is very threatening. How can I report or do something to stop the number and find whoever called? 

Do you have any tools blocking spam, threats, or anything on my phone? 

Gracias