Right bumper replacement parts

My right bumper started acting up and its really annoying to play Monster Hunter with it. (HBG main)

Tried disassembling it and cleaning it with can of air, vacuum and electronic air blower.

Seems like actual hardware issue.

I would like to know if there are any places where i can buy replacement parts?

closest i found is

http://www.westingames.com/Original-Righ...

but apparently they dont do "retail" and does not want me ordering 1 piece only.