We offer replacement pedals that are separate from the crank. Left pedal only is part number 81221011. Right pedal is 81222011.
It's possible they were mistaking yours for the older style. We used to use bicycle style pedals that threaded into the crank. We only have left replacements of these now, so if someone needed to replace the right side, they would need an entire right crank/pedal assembly.
Here's a link to a couple pages from our parts catalog showing the MirageDrive parts guide:http://2010.archive.hobiecat.com/suppor ... _Parts.pdf