Just on a general note:
Be careful with buying codes of prepaid card from strangers.
Also, use escrow. Not difficult.
I am afraid it is not that easy.
If you are not sure of the actual orginating source of the prepaid payment option, you should be very careful. Did the codes come from a legit source, or is it attached to criminal activity. In the latter case, you may think you're completely okay, until you find yourself in a host of legal trouble, and then - unfortunately it's to late to avoid the trouble. Even though you are rightfully 100% innocent, law enforcment will have to establish that fact before agreeing with you, and that procedure is not always the most pleasant to go through..
Personally I would never buy a code for any prepaid payment option from anyone but a reputable seller or reseller, that doesn't include internet strangers.