I would but i openned it to have a look so don't know if they'll help, i will give it a go.
1st
Maybe some of the guys here can tell you how Logitec dealt with their returns. For instance was a replacement sent out without testing the returned one? If so then you havnt much to worry about opening it.
2nd
Their is quite a large modding community for G25 so Id estimate you could make a few quid off selling this even damaged. Its got to be worth £60 with pedals and maybe more to someone needing/wanting spares or modding.
3rd
Thier has been an issue with the G25/G27 wheel adapter even since beta stage that sometimes the G25/G27 pedals on some games and GT5P being one were the brake sticks at about 5%. The only way to release it is to give the bake pedal a tap. However this is far from ideal and can ruin your lap. It aso seems to happen at random. Now I believe thier is a newer shaped adapter available but I cant confirm if this also has this issue or has fixed it so maybe raise the question on a specific forum suited to sim racing.
4th
The latest drivers and new feature the Fanatec wheel offer make it a much better wheel, based on the wheel over a G27/G25. Ive always had the opinion that the standard Fanatec pedals are not as good as Logitecs. However the Clubsports are regarded by just about everyone as better. Stega a guy on GTP forums bought the $200 brake mod for his G27 and he still maintains the CSP are better with their upgrade kit. Im also not a massive lover of either brands shifters, too toy like and usually drive with the wheels own paddles.
Its actually possible to use a joystick as controller no.2 acting like a sequential shifter on GT5 similar to the one on the Logitech DF-GT wheel. Consider this if you have one and for some cars you may like the sequential.
Personally
I would sell off your damaged G25 and buy a GT3S V2 with CSP pedals. I base this on having more features, a more precise wheel and that Alacantara leather is much more comfortable. Also the pedlas are much more adjustable. Take it all into account and for the little extra this would cost over the G27 I think its hard not to see the benifits for the difference in price. Now if the G27 was £180 it would be harder to weigh up the benifits to that price point. The 27 in my own opinion is overpriced in comparison.
Additionally
Fanatec will have a Clubsport based Shifter arriving next year but its going to take a while in coming being Fanatec.
Sorry its a long reply but well hope it helps.