long story cut short, i bought xbl gold on a credit card for a year,
3-4 months in i changed credit card, my xbl was locked so i phoned them up
and they gave me prepaid codes for 12 months xbl.

i've used one 3 month code, and i've got

2 - 3 months
2 - 1 months

3 months = 15m
1 month = 7m

ygf or middleman.
pm me.