@awildcoopixe Here is the thing with support, and this is mostly true for most game support out there. They cannot alter data in any way. They can help with account issues, technical issues, missing content issues, etc but they don't have the ability to reset data. Now some mobile games can with tools if they have them, but I've been in the games industry for a very long time, and it is one thing that a lot of companies simply do not have the ability to do.
When it comes to an issue like achievements, posting on the forums doesn't get it resolved as Community Managers are not game developers. We don't fix the games. We can report issues if there are enough players making the same claim, but support would do the same thing. At the moment there are not a lot of players having the same issue.
If or when an achievement issue is escalated, most of the time the dev team for said game has to reach out to that platform anyway and they also have to look at it.
When you contact Xbox, you can contact them in two ways. There is a "community" support and their official support. The community support can only advise like other players. They cannot fix issues unless they happen to know the troubleshooting steps that resolve it. So contacting the publisher only works in certain aspects. Achievements is not one of them unless we have more than just one player having that issue.
Being that it is on 360, in a support environment, it is considered a "one-off issue" unless it is happening to a lot of players at the same time. So if troubleshooting does not resolve it, it is reported as a bug until we have more players reporting it. Players reporting on other sites like Reddit, Steam, GameFAQ etc we cannot use because they aren't posting here.