Upgrading from PS3 Trial

My friend recently purchased the ps3 version of the game and installed the free trial first--she has a registration code and everything but PSN won't allow her to register her game and upgrade from the free trial before the trial is over, which is frustrating because of the restrictions placed on trial characters. When she tries to end the free trial over mogstation it wants her to put in a registration code for the PC version of the game, which she doesn't have. Is there any way she can preemptively end the PS3 free trial?