The Music Room

Late to the party here but my experience with them was also good.  Very professional to deal with and two very heavy monoblocks were well packaged and promptly shipped.

TMR are making a living in the very tough used audio gear market.  If it was easy, everyone would do it.  Their prices are not too far above the general used marketplace and they, unlike sellers here and on USAM, offer a no questions asked return policy.  I purchased a pair of very heavy and somewhat expensive mono amps from them, that I may not have purchased elsewhere without the option to return them if I didn't like them.  It doesn't get much better than that in the used marketplace.

Regarding what they pay for used stuff, that is entirely their business based on their internal market research and perhaps even search requests they receive from their clients.  I have traded in gear to them that I might have sold on the open market but trading it in was a good way to get the deal done.     

This is ridiculous. If as you say your amp was a "no brainer to sell," then sell it yourself.  If you don't like their prices or conditions, then don't deal with them....simple. 

TMR runs a well-managed business, they stay true to their business model, and the results of that model have allowed them to stay in business longer than most who play in the same arena.  TMR has cultivated a client base by;

• Careful buying of gear/speakers that are in relatively good operational and cosmetic condition
• Internal inspection of the gear/speakers before putting items up for sale
• Relatively competitive prices for the age and condition of the gear/speakers they sell - not the lowest price you will find but in most cases well within the range
• Excellent packaging and shipping practices
• Stand behind the operational and cosmetic condition of sold items
• Offer a 30-day money back return policy (virtually unheard of in the used market!)

As stated previously by @rikkitik 

If you don't like it, and aren't going to use it, send it back and we'll refund your money". 30 days after purchase. Their return policy is good as gold. You might pay a little more, but pretty much, satisfaction guaranteed.

I confirmed that return policy with them before purchasing a pair of $7K amplifiers, which I ultimately decided to keep.

Nobody and no company is perfect.
However, there are many here who have had very positive experiences with them.
The person who needs to look at your equipment could be out sick like many other people with all the viruses going around now.
I do agree that somebody should be able to tell you something, like your place in the queue or an estimated date when you should expect to hear something.
Maybe be a little patient and call back in a couple of days.
We have a saying at work, “don’t assume bad intent.”
Good luck.