DNNA does not have an 800 number for tech support. It's a toll call. This is the process to RMA a Karma:

1 - Call DNNA and report the problem.

2 - Be told by DNNA that you need to fax proof of purchase to them to "activate" your RMA. I was told, and I assume MIlo was as well, that you will be contacted by DNNA telling you that your RMA is activated. I never got such email.

3 - Send the Karma to Irving, Texas.

4 - Wait

5 - Wait

6 - Wait

7 - Call DNNA and get more lame excuses.

Repeat 4-7

Hope that helps.