How long ago did they do the work? Most places warranty their work for ~1 year. Other do longer... Pics would help too. Oftentimes, the base coat is kinda dull, and doesn't have much luster, and the clear is what makes things shine. The other type is a combo base and clear in one coat.
I'm assuming that what was done to your car was base, then clear (two layers), and that the clear is pealling. Is this right? If so, I doubt wet sanding will help much.
If you plan to wet-sand the whole car, with no prior experience, I say don't touch it. If it's just a small section, give it a try. Practice on an old riding mower (really old) or anything to see if it's something you think you can do. Just my advice.
~Eric