If you are still willing to do the shops, tell her you would still like to complete, but will need an extension. Emphasize politely that you will need to cancel the shops/route if an extension is not approved. Provide dates that you can complete them.
If it is not in the cards for you to complete at a later date, then nothing more you can do but cancel.
When I communicate with a scheduler on a shop that I know will not present any conflicts, I add a sentence to the effect of "go ahead and assign." But you communicated to the schedulers upfront about waiting to hear from others, so the scheduler should not have assigned w/o contacting you first. There are a host of reasons she might have assigned them w/o doing that, under pressure to get the shops assigned, in a hurry and forgot to reply back, overlooked your note, or worst case ignored it. None of those are your problem because you were clear up front.
I don't see it much different than when schedulers collect offers. They generally go with the most reliable low bid. So sometimes our offers are not accepted and I seriously doubt there is guilt or remorse when doing so. But shoppers work the opposite. The priority is to accept the offer that will get you the best cash and return. Take the money and run !