Not sure how this question went through multiple reviews: 

https://askubuntu.com/questions/507573/how-do-i-get-a-zte-mf667-usb-modem-working

But we should be more careful when people recommend reinstalling with no information on to whether or not that would fix the person's problem. Voting to close due to lack of information is fine, but no one left a comment or anything to drive the question to completion and instead left the not-so-useful information on the question. :-/

- "I have an itch in my shoe" 
- "Well then, let's chop the foot off."