Unfortunately, I have no experience or knowledge with the trade-up process to answer your question. But as a Juki owner, if I were having multiple issues, like you have, within the 1st year then I would definitely be on the phone with Juki headquarters (i think in Florida) pressing them until I had a satisfactory resolution.
I've had to call Juki and they were wonderful prompting my local dealer to adjust my machine (at no cost to me) and it was done within a few days vs weeks. Hopefully, their intervention will help you come to a reasonable solution.
BTW - it's my experience/opinion that the Juki DX models are completely different than the TL models - it's like comparing apples to oranges . While I love my TL2200qvp mini - I just couldn't find the love with the DX2000qvp when looking for a decorative/utility stitch companion machine.
Good luck!