I did the same damage to mine a not long ago. I used the bumper repair stuff from Isopon with good results (i got mine from Halfrauds - more for convenience as the store is close by). It's like standard filler but is flexible (& black). Repainted my bumper & looks good, you would have to be looking hard to see the damage. Bending the inner steel section of the bumper back out was the hardest part.