Fashion design issue

Fashion design issue

I have 6 sims doing the fashion hobby. I have gotten all the way to where I only have the last item to get twice now and have lost my progress cause it goes to a guest to get the long hair and I loose all my progress. That has happened two times now so I start all over. I don't get to finish the quest cause I never get the last item. I have 2 sims at level 6, two at 4 and two at 3. The first time it happened I was only using one sim. Then when it happened a second time I added 5 more sims in hopes that I could complete it this time. I have had all the items except the last one for 3 days now. All I am doing with those 6 sims is fashion. It is going non stop except for keeping their bars full. I really want to finish this to get different hair styles. If it does not give me the last item when I Should have had it long ago I am not going to be happy. I would appreciate any help on this. I am getting very disgusted with this whole thing and not sure what else to do. Thanks.