Just be patient.
I'm having the same issue.
It took almost 6 months last year to get a MAWD back from repair.
I wasn't in any rush, but I did want it back.
I got it back fixed , no charge, so really I happy with that part of the service.
You might be better off buying a new one in the mean time.
The last time I had to contact them (last year) I had better luck trying the phone as I remember it took a couple of tries to catch them in the shop...
Thanks for the suggestions. I kept at it and now my MWAD is on it's way back to the great white north for a little TLC. I'm hoping to have it at the January CATO launch as it's my favorite (and easiest to use) altimeter...
ps if you're new to altimeters and DD, this is the one to get - it's very easy to use!