I respect the fact that pt999 might prefer the May over the Musetec and would be willing to pay the difference. One cannot argue taste. In one of my recent posts I have said the same. By the way, IMO it needs more than a week of break-in due to some very special capacitors in the analog section.
However, about your purchase and return. Sorry to hear of your dilemma. To my knowledge this is the first reported return of a Musetec. I have never bought from Shenzhen. They seem to have been in business for a long time; they seem to do a lot of business. Up until now we have only heard positive things about them like honoring Black Friday prices beyond the sale dates and pretty reasonable shipping times.
Their "30 Days No Reason Return" policy reads as follows: "After returning the product to the address provided by our customer service team, we can send you a new item free of charge (we will reimburse you the return shipping cost), or you can choose to receive a full refund. Please contact us for Return Material Authorization within 30 days of the order being received." It is pretty simple and pretty clear.
If they don’t honor that policy TO THE LETTER, then that’s what credit card charge-backs are for. Communicate with your credit card bank. Just make sure that you have not already paid your credit card bill for that item until after you challenge the charge and deduct it from your payment. With a 30 day return period that should be easy to do.
All of this seem pretty straight forward and, personally, I would have no problem ordering from them. I have learned to deal very effectively with situations like that. But I can understand if others would avoid.
Finally I would say to pt999 that if Shenzhen persists in these charges you might want to report this to the FTC, and tell Shenzhen you plan to do so. The FTC takes reports like this on-line.