Brunch Bagel is, if my memory serves me well, on a side street called Ezer Yoldot. Here's how you'd find it:
From Kikar Shabbat, have your back toward Mea Sha'arim, and face Malchei Yisrael. There is a bank (HaPoalim?)on the corner at Kikar Shabbat.
Walk past the bank and turn LEFT at the very first little side street you encounter, which is Ezer Yoldot.
This street is a little bit steep going uphill. Walk up this hill a bit and Brunch Bagel will be on the LEFT side of the street with a RED sign.
Now, if you DO go back to see if it is still there, please report to us if you do find it. And, if you sample their bagels, of course, we'll want your opinion on them, too.