Can anyone recommend somewhere in the uk to buy the little bands to tie up top knots  please? Either shops or online.
 
I can't seem to keep anything in the two younger ones hair.For my older girl I use either very tiny scrunchies, babies tiny plastic hairslides, or little latex bands that I got once from a stationers (now shut down) which work no problems, but not with the two young ones 

Within quarter of an hour they're either hanging down over one eye, or disappeared altogether! 
So I obviously need to use the correct thing.......whatever that is