310 bar comes up with 4492 psi for working pressure. i would assume its billed as a 3000 psi bottle with that extra bit for a margin of error/ safety
http://www.ukdivers.net/science/calcs.htm
who sold it to you?? if your that pissed send it back
still, most places only fill to 3000 psi anywho, its only at tournies (eg masters, capaign etc) or if your local training place is willing to fill to 4500.most places i go to there is a man with a 3000psi dive bottle and an adapter...sometimes its even a girl