Your sig image location is:
http://i302.photobucket.com/albums/nn120/daxter849/Ertty.gif
Mods can't delete your images, they can only remove the html that displays it. The image is still wherever you put it - in this case, it's on a Photobucket server.
If your image is 1MB, then every time somebody displays a thread with a post of yours, it takes 1MB of your allowance, plus a small overhead for every time it's repeated on the page for multiple posts. Given the average post view is around 200, that's over 200 MB per thread.
The answer is simple - make your sig a decent (smaller) size and attach it to a post as Cash says.
If your friend doesn't understand how GIFs work, that may be the biggest part of your problem. Each frame should only store the differences, not the whole image. Colours should be blocked and simple, animation should be selective.