The Isis Adventure

I think my Isis I is broken, I have had help and have followed that help to the letter. I have watched the youtube video numerous times and nothing. I can get the thrid bb released and it stops sounding but then the plunger goes all the way in. I am staring to believe my Isis I is broken and I don't want to spend the 24 pounds on a chance that it might be broken. Please (I don't mean to be rude in any way) don't tell me to "keep trying" or "you'll get it" because I have heard enough of that already. If my luck would have it I am probably the only one with an Isis one still locked. If you are willing to help I can say ahead of time that I appreciate it. PM me for a full description of my problem as I don't want to put my full problem on the forum becayse it could disclose info on how to open it. Thanks