there is no way to get your money back or get it returned because they are sold as is and the person saling it knows it won't work. thats why you got the cheap deal on it.
they ran up a charge on the account for big bucks and never paid the bill and the unit's id number was banned from the gaming network for the rest of the time it is on earth and they won't un-ban it.
if you want to buy a used gaming unit. then do so in a brick and mortar store that HAS a return policy for them, they
have insurance to cover the bad units and can take them back and toss them without loss of any money.
BUT YOU DON'T, unless you were able to buy it with a credit card then they can stop payment but the dirty varmit you
tried to buy it from now has your credit card number. so its just safer all around to buy it at a brick and mortar store.
you can not tell it has been banned from the gaming network until you try to connect to the network. and it is banned for life they even ban it on all their networks they own. so its no good anyplace.
if you stop and think why is it such a great deal on the unit? BECAUSE THEY KNOW THEY GOT BANNED FOR LIFE.
