if i buy a subscripion for a month can i un subscribe from it at anytime

Yes, just be sure to go to "My Microsoft Account," then go to
Services & Subscriptions, then lastly go to the Xbox Gold Subscription section and click on
manage, then press "Cancel Subscription."

With my Live expiring on 1st Dec, I went with the 12 months (+2 months bonus) subscripion from Tesco. So the game cost £25. Worked out pretty well for me. Cheers.

You can cancel anytime.

There is no waiting period.

Do note that even if you cancel right after buying it, you'll be able to use the same for the period for which you initially subscribed for.

If you intend to cancel, do that before renewal date or you'll be charged for subsequent month.

Tell me if I'm wrong, but as far as I know, you cannot purchase just a one month option outside of monthly subscribing.

If you don't want to subscribe on your account, the only options you have are 3, 6 or 12 months. The one month options to buy outside of a subscription are for new customers only.

Where did you buy this from? I suspect this didn't go through and is the reason it didn't extent.

I can buy Gamepass Ultimate for 1 month and I buy it there for years where I bought this

Tell me if I'm wrong, but as far as I know, you cannot purchase just a one month option outside of monthly subscribing.

If you don't want to subscribe on your account, the only options you have are 3, 6 or 12 months. The one month options to buy outside of a subscription are for new customers only.

Where did you buy this from? I suspect this didn't go through and is the reason it didn't extent.

I can buy Gamepass Ultimate for 1 month and I buy it there for years where I bought this

Gamepass Ultimate only became generally available in June last year. You can purchase a one month key from lots of retailers, but if you try to redeem it, it shows an error and states that it's for new members only.