She probably just wants you to keep buying Deva. It kind of makes me annoyed that she just brushed you off with "there's nothing else that compares"... there are TONS of products out there, there's bound to be something for you!
You need to determine what ingredient you reacted to. I'm assuming it was probably the wheat protein, but it could be a combination of things. Once you determine the allergy, and figure out your hair properties (fine, medium or coarse? high, medium or low porosity? and so on), maybe you can try some other curl-friendly products from lines either in the drugstore, in salons, or online ones like Curl Junkie, Spiral Solutions, etc.