You would need to contact Microsoft as they handle billing.
If you really go on their nerves and call them every day you are going to get your refund.
Then you need to asure that you make a little bit of confusion. Write down if the person you are talking to (write down the name) says something weird and not true. (For later usage) Complain about who told you what and bring them in trouble through it.
A call center employer isn't the smartest person out there if you use the right technique you can always
get what you want!
I have made very good experiences in the past to say the least.