Couple questions: is it on the rim of the charging port? I got one from removing my charge cable at an angle and it twisted and gouged the plastic on the way out, which leads me to my next question, is it deep? Like is it superficial or is it more like missing the gloss finish and possibly some plastic?
A usful product to have for glossy finishes is Displex, it works amazing on this phone. I am incredibly anal about high gloss finishes and blemishes showing up on them, even if i can only see them in direct sunlight. If you use this product with a cotton swab and gently but firmly rub in a circular pattern the scratches will go away very quickly, if you do it too much or too forcefully you may cause a bit of a clouding effect you can notice in strong light, so just do it for about 30 seconds and wipe it clean with a micro fiber cloth and do a little more, you should need a pea sided drop altogether, this will last for quite a while, just make sure you squeese the tube up and down to kind of mix it if it's been sitting a while. If the blemish is more of a gouge and not a fine scratch then this wont work as well, what it does is polishes the edges of the scratch down and fills in the bottom of the scratch with what's being polished smooth, so it works wonders for small problems, with larger issues you'll end up with a smooth ripple in the plastic as it will wear the hard edges down but obviously won't rebuild what's missing. I was reluctant to use it on my captivate cause it didn't do squat to my htc pure, but it performed remarkably on my captivate, just be methodical about how you use it and when you're done and your scratch is gone to your satisfaction be sure to put a little(and I mean little) on your micro fiber cloth or incredibly soft rag and buff over the area back and forth in one direction, for me that helped eliminate any cloudy effect and polish it back to a brand new phone shine. Just go into Google shopping and search for Displex, it's very inexpensive.