If you actually call the number, it gives you an option to put your number on a do-not-call list. In fact, it's the only thing you can do when you call the number, soooo.... why don't you try that?
Just have looked at my phone and realized that is was an unknown caller. When I typed in the 234 number, it came up as a scam. Don't worry, just block the number.
My husband got this call on his phone. We do not answer calls we are not familiar with, so I looked it up here. It will go to our auto reject call list...I doubt it will do any good, but it is the best I can do.