How to reattach driver side seat back?

[nickstl77]

Noticed tonight that the back "piece" of my driver seat is coming loose. I'm not sure what the actual part name is, but it's the back of the seat that has the storage pouch on it etc. Underneath it is the cushioning and heating/cooled seat stuff. I've tried wiggling it every which way but it doesn't snap back into place no matter what I do...

[Green 1364]

Dealer broke mine fixing the heated seats and had to order the plastic piece inside which has clips on it. There are also 2 stretchable pieces that attach under the back, bottom of the seat. If you Google the seat parts you'll see it.