Actually, I think your intention isn't that of legality. What you did in your thread was not selling prepaid cards for honest profit as the other resellers here are doing. What you're doing is selling off the credit and then keeping the empty cards for company reimbursement. That is just plain cheating. Even now you've opened a thread to buy empty cards for the same purpose.

You're just pissed because your thread got closed and now you're here dragging down other people's businesses. Be aware that your thread got closed not because it was illegal but because of you trying to gain profit in an underhanded manner.