OK.. I have a problem (not me my truck

).... I think??
I bought one of the "brand new" billet grilles for my '78 from ebay about 6 months ago. When it arrived I checked the box for damage, cracked open the end of the box and slid the piece out about 1/2 way. Everything looked like brand new so I slid it back in the box and put it on the shelf for later.
Well, now is later. I pulled the grille out of the box and proceeded to install on the truck. This is where the problem is. I believe I have received a grille for an 81-87? It has about a 3-4 degree bend in the middle of the grille? Because of this bend it does not look right nor fit properly in the grille opening? I thought all grilles for 73-80 were completely "flat"? No curves, no bends or anything?
Am I crazy or is this the wrong grille? I have emailed and called the vendor which I purchased this from and they deny that it is incorrect. I have offered to pay the difference in shipping to have the correct grille shipped/swapped to me but I think I am being stonewalled. I do have a reference picture/auction from someone else selling the same "bent" grille and stating that it will fit a 73-80 pickup.
Anyone ever used one? Especially on a 73-80? Did I get burned? Should I just cut my losses and sell it off and buy the correct one?
Thanks,