Not sure about the hang up, however truth is I call the New York number, listen to a very long winded "Welcome message" on a machine, Finally it allows you to hit "9" I believe is the #, and it connects me to live customer service everytime.
No problem with communications, I sent my Cartridge into them Jan. 21st or 22nd, came back on about March 15th to 20th. So about 6 weeks like they say. Also I paid 19 bucks extra to make sure they expedited it back with 2 Day fed ex shipping.
No issues beyond that, perfect service, good enough communication, Zero issues with the quality of work and of course the sound of this sucker is super sweet!
My only suggestion is that its VERY possible the more exotic the cart. or simply the more a "Pain in the Ass" it might take longer to dissassemble and get correct, so unfortunately you get pushed back on the basic economics of it when he has 10 bread and butter denon carts sitting there all getting the same "Flat Fee cost" that can get done in 2 days vs. 2 weeks of work or special parts, adhesive or whatever.
I can't even tell how some of these carts could easily come apart to be cleaned, aligned, and signal tested, which from my understanding they go deep finishing and testing these with even perfect channel matching balance. Probably lots of microscopes involved I don't know!
Just a guess I don't know but there has to be some strange reason with the inconsistencys, because they take no payments up front and probably for good reason, they can't evaluate until they really get it in the shop I assume.
Plus if 50 people send these in all at one time I can imagine vs. if they get only 15 in one month instead? I have to be honest we have no clue how many go, there could literally be a back room with 1000 little boxes all virtually the same sitting at one time of virtually 2% to 20% of the audiophile population in the world sending their cart. to these guys, and they simply get lost in the shuffle.
Good Luck