Manufacturer Repairs? What is a reasonable time?

I sent a solid state amp back to the manufacturer in the USA on March 16 for a minor repair - one channel input not working - despite 4 phone calls and 4 e-mails - he hasn't even started the repair. Doesn't respond to emails but does answer the phone and says he is busy and is alone. I Will not identify him yet, since I'm not sure what the "norm" is, since I have always been thoroughly spoiled by Bel Canto, Atmasphere, CJ, AR, acoustic Zen, Cambridge, EAR, who respond immediately and usually have my unit back in 2 weeks. So when do I start to play "ugly", realizing that the economy is bad and manufacturers may be struggling?