"The first time you link your account and have something sent to your wall, you get a special achievement and 100 Cash Shop Credits!"

i linked it

"EndlessXendever has gained the achievement Link Facebook Account."

and had it set to post to my wall. it didnt work :(

It shows that you have the achievement. Did you check your inventory for the 100 Credit Gift Card?

OH. i didnt know you got a gift card! i thought it was cash. haha. Thank you

Nope, it's a gift card. You can redeem it for 100 CSC though, which you can then spend. :3 No problem though!