My first Rolex

[DJRE]

Hi - I just took delivery of a 2008 Explorer II (black dial). It arrived last week in perfect condition. However within 24 hours it had picked up a small scratch on the Sapphire Crystal. I am not aware of having knocked it on anything other than my wooden desk in that period so was very annoyed and surprised to see it scratched especially as the sapphire crystal is supposed to withstand most contact other than diamonds / other hard materials!
I visted my AD at the weekend to ask whether it was possible to polish out the scratch. They said that the only thing to do would be to get Rolex to replace the crystal (£100 cost). I'm weighing up my options at the moment. On the one hand I'm reluctant to spend more money on getting it replaced (having spend the best part of £3K on the watch!) but on the other hand every time I look at it I'm drawn to the scratch which rather takes the shine off a purchase I've waited years to make!
I've seen internet treads about using grades of diamond paste to successfully polish out scratches on the crystal but does this actually work as the AD said, categorically, that it does not! Depending on people's thoughts about its viability I am tempted to try to polish the scratch out using the paste but is there a risk in doing so that (i) it may cause further damage; or (ii) Rolex may refuse to replace the crystal if it has been "tampered with" in this way (I've heard stories about things like this in the past!).

Any thoughts would be much appreciated!

Many thanks