If in doubt (which is quite often when it comes to tyre/rim sizing

) I always try to find or measure the ISO/ETRTO number (something like 15-622, 52-559, 44-584 etc).
The smaller number is the nominal tyre width/depth or the internal width of the rim section, and the big number is always the diameter of the bead seat of the tyre/rim in millimetres. This larger number should match both tyre and rim.
It's not the rims that are 28" etc, it's the nominal size of the tyre/rim combo. BITD when roads were rougher, tyres were fatter and everyone used fixed gears or hub brakes, the rim size was less important than the overalll diameter. All the 700A/B/C range were approximtely 700mm (27.6") in total diameter, and would fit the same frames... A "700c" wheel like LGF's has a rim only 622mm in diameter, but that size used to be the fattest tyre in the 700A/B/C range, originally having a 38-45mm tyre, so 29ers are really retro...
As the others have said, your 28 x 1-1 1/2 is either an old British roadster wheel, or more likely a newish 700B French/Dutch roadster. At 22 x 635 it's both a bit wider and larger than a 15 x 622.
Good old much missed Sheldon Brown's great for this stuff...
http://www.sheldonbrown.com/tire-sizing.html
If they told you it was a 700c, ask for your money bay and try another LBS... :shock:
All the best,