As far as I can tell, the initial motor stall event resulted from the shaft collar being positioned incorrectly, or slipping due to not being tightened sufficiently during assembly. That is what caused the motor to stop initially. It is hard to say when the barrel bent, but if I had to guess it occurred after the stall protection board's limit was increased, and then the motor was switched on before the plastic had fully melted.
Pouring acetone down the barrel is not likely to help, and will make future heating of the barrel dangerous. Given that the barrel is deformed, it will take some significant force to slide the auger out of the barrel, with the plastic heated above melting temperature. I've done it before two different ways:
1.) Use a long C-clamp to press the auger out, pushing from the nozzle side of the barrel.
2.) Use a set of pliers around the auger, between the shaft collar and flange to pry/work the auger out of the barrel.
You may elect to replace the auger and barrel instead of attempting to extract the auger, that's up to you.
It would also be a good idea to check the internals of the gearbox for damage from the thrust force ending up on the gearbox.
Replacement parts are provided in the case of something being defective/DOA, but given that it is a kit we cannot cover damage resulting from incorrect assembly. We have no way of knowing if it was assembled correctly, stall protection was set correctly, etc. What we do is provide inexpensive (i.e. our cost, no profit) replacement parts after talking through the situation with the customer so that the scenario is not repeated.
If we just put parts on the website, folks would be likely to repeat the same mistakes and become frustrated. That is why parts can be requested via the contact form on the Filastruder website (mentioned in previous post). I'm happy to provide a replacement barrel at no cost in this case.