Try putting a cleaning rod down the bore and see if it goes all the way to the bolt (unloaded condition). If it doesn't, the rifle is loaded!!! If not, check to see if a round is stuck between the magazine and the rear of the carrier.
A gunsmith could probably fix the rifle in a half-hour. I'd call the company and see if they have a repair station nearby that you could take it to. You won't be able to ship the rifle with rounds in it.
You can remove the cap from the magazine and take the rounds out of the tube that way. Watch out that the spring doesn't go flying when you remove the cap screw. After the spring tension is removed and live rounds that aren't stuck in the tube are out, you may find one round still stuck between the tube and carrier. It may be possible to use a thin screwdriver or piece of metal to slide the round to the magazine and out.
If there is no round in the chamber and none in the action, but the action still refuses to open, you'll need to remove the lever pivot screw from the receiver and the lever may come out. The action should then be freed up, unless there's a bad cartridge stuck in the chamber.
Good luck. I wish you were nearby as I could probably fix the rifle in short order.
“God save us from people who mean well.”
― Vikram Seth