J.,
I'm sorry you are going through this. My son had chronic constipation/encopresis when he was younger. I know how frustration and absolutely maddening this can be! Try to relax and move forward instead of focusing on the things that haven't worked.
My advice to you is to talk to her doctor. If chronic constipation is causing her problems he or she will be able to help. If your daughter has encopresis she no longer has control of her bowels and may not even feel it when she needs to go. This situation can be very rough on the entire family. The good news is that with treatment it can and does get better. My son is eleven now and aside from the occasional "skid mark" I can't remember the last time he pooped his pants.
If there isn't a medical problem you might want to back off and put her in Pull-ups for a while again. Maybe she isn't ready. This isn't a race or a competition. I know that might sound crazy, but it is very important that you not let this become a negative experience for her. She shouldn't feel bad about herself (and you shouldn't feel bad about yourself) because she isn't a good pooper. If you are crying and emotional about it, it is bound to become a bad experience for her- just back off until you are both ready to try again. Eventually she will use the toilet.
Good-luck,
K. L.