From one who knows absolutely nothing about these guns, but A LOT about commercial entities, let me speculate a bit about the problems you're encountering, and suggest a solution---and then speculate a bit more about the REAL problem.
Actually we'll do it hind part to, and deal with the REAL problem first crack out of the box---because that's the way I've been trained---and the way I worked. My training comes from what I call Problem Solving School. That's where the very first thing that gets beaten into your head is to make sure you know what the REAL problem is---lest you waste valuable resources trying to solve symptoms---or apparent problems.
So---what's the REAL problem? I see the REAL problem as an entity who's philosophy goes like this: We will be successful if we build our products at the lowest possible cost---and also operate our support services at the lowest possible cost----rather than build our products to be the best possible for the price---and operate our support services with the best staff possible. The symptoms I see are, on the one hand, what I see/presume is a fairly new product that doesn't work as it's supposed to---and a woefully understaffed service facility---which is incompetent to boot! (12 weeks spells understaffed--or a flood of defective products---or both.) (Returning a still defective product spells incompetent---or a haste makes waste environment----to keep costs down.) Combine the two as a recipe for failure.
Are these people stupid? Not likely---just hamstrung by penny pinching.
So what about my gun? You have three choices: 1. Keep on beating a dead horse with the expectation of reviving it. 2. As already suggested, have a go at fixing it yourself------and likely learn something worthwhile along the way. 3. Find someone who gives a rat's behind about their customers---and KNOWS how to fix your gun. And #3 requires that you not fuss and fume about having to pay this someone.
Me? I vote for #2---because I've been there and done that! What that got me was NEVER having to pay anyone to fix my gun-----not counting when I was maybe 16-17 years old, and managed to lose a hammer screw off a French made, muzzle loading, double barrel shotgun---a hammer screw with an engraved head, and with a slot that formed part of the engraving pattern on the lock when it was tightened. I found a someone who could do and did that---and then I fussed about the cost. That was explained to me like this: "Half was for my time. The other half was for knowing what to do."
That was the first AND LAST time I ever fussed about the fee charged by a professional---and that has served me well!!
Ralph Tremaine