i2501 is normally a payment issue and very common with the mog station, however we have seen in the past, that this also applies apparently to non purchases, and just is a problem with their mog station itself. Besides waiting for a couple of hours, there's not much you can do from your end, with that said, since you mentioned it has been a week, my advice tomorrow is Mog Station Maintenance, as well as Server Maintenance starting Jul 3rd @ 10 pm pst and will end Jul 4th @ 3 am, it can finish earlier or later, keep an eye on the news section. This might or might not fix your actual problem, but as it stands right now, that would be your only bet, if you are 100% sure that the code is valid and is not the valid EA code or some other mix up.