I bought a xbox 3 month gold membership, however it says my memebership is limited? How is ...

That does seem unusual. I'd contact Xbox Support and they will be able to see the type of subscription on your account and they can probably help from there.

You can contact Xbox Support here -
https://support.xbox.com/contact-us

If you're in the states you can call them at 800-469-9269

i have bought 3 months x box live gold memebership how do I activate it

The is a joke. i make a account and it says 1 month gold free memebership when i try and get the 1 month gold free memebership it says error code and i don't know how to fix it ? would you mind telling me and other if you can or if it isn't going to work
and if not does it mean i need to buy a gold memebership for it to work ?

No I kind of agree. I paid $24.99 for a 3 month xbox live gold membership, I played it for a month and a half, and didn't play for a while after that. 2 or 3 months later when I go to play online, its says my gold membership ran out. Its *** up that they
charge you when you're not even using your xbox. I payed for 3 months of gold, only used 1 and a half, and even when I wasn't playing they were taking time off my membership. They should only charge and deduct your membership when you are playing. I bought
3 months of gold membership, I deserve 3 months of gold membership. So time of the xbox gold membership should only be taken off when you're logged in.

Sorry to say but the trial gold memberships don’t work if you already have an active gold memebership