You need to put down about a 4 inch layer of mulch over weedcloth to stop most weeds. Even then, you will get a few that find their way, as dirt will blow on top of the mulch. However, they are easy to pull out. I'd spray them with Roundup and put more mulch.

Are these "weeds" growing through your newspaper layer or are they growing in the mulch? If they are growing up through the paper then either the paper layer was not thick enough or the "weed" is a lot tougher than normal, but that does happen. If the "weeds" are growing in the mulch what did you use for mulch? I have used shredded leaves, wood chips, grass clippings, and stone for mulches in different areas and have not had "weeds" grow in any of those mulches for a year or more, never in a matter of weeks.
There is never a reason to use any of the glyphosate products, except to generate more dividends for the companies stockholders.