How do i change my Xbox Live Gold subscription from Annual to Monthly? It wont let me do it...

I couldnt pay gold, but i didnt have any other dues, but now its says i cant change it since it expired

you try change the Option in https://account.microsoft.com/services/ ?

has your Live Gold expired and do you have an overdue balance?

if it has you may need to pay that before you can change the subscription

Just turn off recurring payments, it will then state that your live end date then past that date just pay for a month. That is unless you have left recurring payments on and went past the renewal date then you need
to pay what's owed as it would've automatically attempted to take payment.

if you have recurring payments turned on (default) if there aren't enough funds to cover the payment it goes past due and that has to be settled before you can continue.

this link provides the information for paying a past due balance (do not use a code as that won't clear the past due balance)

https://support.xbox.com/en-US/billing/xbox-subscriptions/pay-past-due-balance-on-xbox-subscription

alternatively, you can contact Billing and request a call back.

go to https://support.xbox.com/en-US/contact-us

in step 1 choose Billing and Accounts

next select See Other Options (below the green "Ask A Question" button)

next select Payment and Billing

then click the Show Contact Options and choose from
Chat with Xbox Support or Request Call from Xbox Support

hope this helps