Posted by Coco

If it was already uploaded and given out, the only kind of edits you can make to it are teeny tiny tweaks like fixing a pixel out of place or adjusting the height or position. Anything else wouldn't be allowed.

There's no way to really prove your stance on this...so unless it's a tiny adjustment like what I stated above, then no you probably can't get it changed. Especially since the hat was made for the guild and not you. If the guild and guild leader is happy with it, then there's nothing you can really do since you already allowed them to have it. I'm pretty sure the guild leader would overrule you in this situation.