Been com banned don't know why

Go check in https://enforcement.xbox.com/ , open a Ticket there and see what they say to you

Hi
dL aDaM x2,

There is always a reason a ban is placed on someone. Have a read of the following please -

https://enforcement.xbox.com/en-us/home/howTo#sub-topic0-3

How am I notified of my suspension?

When XBLPET issues an enforcement action, an email message is automatically sent to the address associated with your Xbox Live account. This address is referred to as your Microsoft Account (MSA). If you are using a child account, an email is also sent to
the Microsoft Account associated with your parent or guardian. Each email message explains that the account was subject to enforcement action and links to pages that provide additional information.

In addition to the email message, affected accounts also receive an Xbox Live message that can be viewed from your Xbox console, Xbox.com, and the Xbox app on Windows 10. Like the email, this message explains that the account received enforcement action
and provides links to more information. Note that if you have received a full account suspension you may be unable to view this message, and will instead be notified upon attempting to sign in to Xbox Live that the account has been suspended from the service.

Feature-specific notifications are also displayed when attempting to use impacted features or apps on your Xbox One console. The specific method of notification depends on the enforcement type and what feature or app you select, but typically include a notification
indicating you are not allowed to use the feature.

https://enforcement.xbox.com/en-us/home/howTo#sub-topic0-4

Enforcement people don't come to the forums and there's nothing we can do to help you.

You need to go here to check out what happened: https://enforcement.xbox.com/

For information about suspensions, you'll need to go to http://enforcement.xbox.com