My account email got changed without my consent.

According to Microsoft:

How to recover a hacked or compromised Microsoft account - Microsoft Support

And have a look at:

Contacting support for a Microsoft Account - Microsoft Support

Contacting Microsoft support about your Microsoft account

Important:

• To protect your account and its contents, our support agents and advocates are not allowed to send password reset links or access and change account details.
  
• They cannot do more than you can do for yourself with the forms available from the website.
  

My account was compromised. Someone changed the inf through XBox.com about a year ago without my consent. The account is still on my XBox, they never recovered it. Also, I rang up XBox 4 times over a year, they refuse to help, since I can't provide the info
for the guy's email.

I'm sorry about your situation yet you have to be the owner of the account to make any changes (including the email associated with the account)

These are the rules and support can't change the data of the account's owner without his/her consent.

Someone used my debit card through my account without my knowledge or consent

Next time you should start your own thread if you have a question/issue.

I'm not a member of the enforcement team but my guess would be the first four letter word of that gamertag was the problem.

For an official answer you would need to post here
forums.xbox.com/.../41.aspx

You get one free name change when you start your account,after that you have to pay.

You used to get to choose your gamertag after a forced name change but people abused that so the rules were changed.