Who called from 2816613542

I answered "Jim" a man's voice said "is Jim there".  I answered "this is he" and the call ended.  4 seconds...

I get multiple calls from this number a day and if someone doesn't get this [***] to stop there will be problems

Called in evening around 8:45PM, Caller ID only shows "TEXAS". The caller tried to leave a message asking for me by my first name, then got confused and hung up. How hard is it to pronounce "Gump" (jk). No idea what he wanted or who he was with. Called back using *67 prefix, muted and on speaker, only got (fake) fast busy signal which was likely set up by them to confuse anyone that calls back.

So how can they be legit, whether with RNC or DNC or "Energy Conservation Group" if they obfuscate (look it up) their name and number?

I received three calls from this number and they were all hang ups. How can I block these calls in the future?