Did you stop working in that LBS ... or, are they all rejects from Wally World?
Look at the sidewall of your current tires ... an abbreviated list of the common sizes (there are MANY more):
700c == 622-xx
650c == 571-xx
MTB/26" == 559-xx
where the 3-digit number is the rim's designation (vs. diameter -- I do NOT know how they actually came up with the actual numbers even though I once read an explanation, somewhere) ... and the second number (represented by 'xx') is the tire's size.
If you have 700c wheels, then you want 700c tires.
BTW. When you do receive your 'brand new' tubulars, you will swear that they are intended for a 650c wheel ... new tubulars need to be "stretched" (and, allowed to "rest") on a spare rim BEFORE being glued onto the rim ... you can do the initial stretching on a spare, 700c clincher rim.
BTW. Apparently, based on laments I have read, some novice users fail to stretch the SPARE tubular tire(s) they carry, and that can lead to some very frustrating moments if you need to fix-a-flat when you are on a 'training' ride.
N.B. Tubulars need LESS glue than most people think unless you are Crit racing ... the more tires you glue-and-use, the less glue you will probably use each successive time until you figure out how little glue you actually need (i.e., how little glue you can get away with using).