I lost achievements because of no internet. Help!

This happened a little while ago but I'm wondering if it can be undone. Last christmas, I got Infinite Undiscovery as a gift and I played it at my parents place where they only have a dial up connection (they live deep in the country). However, shortly before Christmas, I was at a friends place and we recovered my gamertag so I could play stupid old CoD with him online. Anyway, I couldn't re-recover my gamertag at my parents place because they have no broadband. At the time I didn't know what I was doing because I was completely unaware of the situation. So, I proceeded to keep playing IU. Anyway when I got back to the city and re-recovered my gamertag I found out that the achievements I got from IU were gone. If I play the game over again, will I be able to get the achievements again? A friend told me that the same thing happened to him but when he went to replay the game none of the achievements would register, but I don't think that's true. It just wouldn't be fair or make any sense. What do you guys think?

Well it sounds like you didn't exactly 'loose' them, you just played a game while not signed into your gamerprofile. I think the only way to get those points would be to play the game again while signed in.

Lol I'm getting two totally opposite answers... does anyone have any experience with this?