I cancelled my gamepass months ago, and when reviewing my bank statement tonight I realized...

I bought Xbox Game Pass way back in maybe September. I forgot about it and realized I needed to cancel it in December (my financial situation changed as I am a student). I went to cancel on the website but it didn't give me the option, so I called Microsoft support and they cancelled it for me. It even says its still cancelled. However, I was reviewing my bank statement tonight because I was curious as to why my balance was lower than it should be and low and behold, I had a charge for "Microsoft Ultimate 1 M" for $16.11. I am extremely upset because I am not able to work right now because of a surgery, and like I said I am a student so my money is very limited. I will be calling the bank tomorrow to dispute the charges, but I want to make sure this does not happen in the future, and clearly Microsoft support did not do the job correctly the first time. Has anyone had this problem? What should I do, and am I going to be refunded?

:)