That is unfortunate, since the rules both in the GDS and the OneWorld PDF allow two without regard to direction. If your ticket has not yet been issued, perhaps a travel agent could book it? If you are trying to do a re-route, I'm not sure what to suggest. Perhaps a different QR office, or perhaps another airline (whose flights you are using) might agree to take it over? You could try AA, but I've heard they no longer take over RTWs issued by other airlines, which I hope isn't true.