What do you do with opened boxes of outgrown diapers? 🤔

Julia
My little girl is 2.5 weeks and she's outgrown the newborn size. I probably should've switched her over to size one several days ago but we're finishing the last package that I opened. She's getting way too big for this size, I don't think I can squeeze her into the newborn diapers after I finish what we currently have out right now. 
I have one package that hasn't been opened at all and two other unopened packages that came from a box but we got rid of the box trying to make space.
I can't remember if the diapers were gifts or not but I don't have receipts for them and I don't even know what store they came from.
Edit: I really need the next size up but I don't think I can exchange them at the store since they're no longer in the box.
What do I do with them?!