Chances are that it wasn't the RMS leaking to begin with, but in fact, the oil pan at the left rear portion of the sealing surface.
Common mistake among rookie techs, go with the quick diag.
They need to reseal the oil pan, unless, and this is just speculation, they rolled the seal for the RMS and f.u.b.a.r.'d it.
Take it back to them, and have them figure it out. A reputable dealership will take of you.