Being Charged For monthly gold when i bought 12 month?

You can check https://commerce.microsoft.com to see what the charge was for as well as how much time you have on your membership.

Recurring memberships are added when you purchase a Gold membership from the console. It states in the agreement that it will be charged on a monthly basis unless you turn the auto renewal off. If you had a monthly membership going before you added the
12 month that will probably be why you are receiving the billing. Give support a call and they can help you sort it out.

support.xbox.com/contact-us

When I tried to change to Ultimate, they said they would charge me monthly. I already bought a Core membership for 12 months, and i just wanted it converted to Ultimate

I was given a one month trial when I bough my xbox that automatically changed to a recurring one month membership. Last month I upgraded the monthly gold membership to a yearly one. Yet this month, Microsoft still charged my account the monthly fee on top
of the yearly one. So I am now essentially being charged for two live accounts even though I only have one! The "contact us" tabs on the Microsoft website don't open to anything, neither does the live chat option. When I tried to cancel the monthly subscription,
the screen said the only one I have is a yearly membership, even though they just charged me the monthly fee last week!!

I live in Ireland, I can't find any other way of dealing with this issue from the Microsoft website.

I suspect that Lollamia might have answered this. Looking at it, despite the purchase date being 15/04/2012, it appears that I wasn't actually charged until nearly a month later, on 12-05-2012. The previous charge to this was on 15-02-2012, which was the
2 months for £2 offer, So when this ended, it rolled over to the normal monthly fee, but didn't appear to charge me until the end of the period.

If this is right, it's a very odd way of doing things, but it doesn't seem like I'm being charged extra.

I have a related question. I had xbox hame pass ultimate but it recently expired and as there were no interesting games out, i reverted to Xbox live gold for 12 months. Now my question is

If i again try and sign up for game pass ultimate how does it work. I have 12 months of gold, does i get it converted again to ultimate lime the initial offer or am I charged a monthly over and above the remaining months (as it says it will convert gold
upto 36 months)