Rope will not retract

I have a 18 inch poulan wildthing chainsaw and it's rather new with little use. The rope got stuck when I tried to start it and would not retract back in. I took it to a repair shop and they told me that the plastic had welded itself together and that i needed a whole new housing for it. I don't see how that could be posible. I ran it for about 10 minutes is all and I shut it off to move a limb. Tried to start it and the rope stayed out.