@Saya: If the top is sticking up(Im assuming its the pieces that were swept back at the crown of the head in the photos?) Try combing out the hair, so the gel/spray loosens. Itll help the hairs possibly lay flatter and pin them down. Then, I suggest put it on your head, grab a headband or bobby pins, lay them flat, and while wearing it, spray so it molds to your head, and not the wigheads shape.(this is how I make my germany wigs and general swept back wigs.)
Sidenote: If you do comb out some of the gel/spray, it helps to have a comb you can dip in warm water. It shouldnt be soaking but just enough so it moves through the wig fiber, like a reeeaally gentle washing. Also, if it knots, dont tug too hard, but stroke the knot, and hold it at the base of the weft affected.
In terms of the top knot, it's probably too heavy. I dont know how the knot was made, but I have a few possible solutions if it can be described better.
(Sorry Naru if you wanna fix it, Im just offering what I can atm! )
Remember! Everything is fixable!