I had a nightmare with my Nav6 (touched upon lightly elsewhere in this forum).
Garmin Support were awful. Sending me templated responses which contradicted what they said on the phone, answering emails 3 messages out of sync,ignoring escalation requests and even stating that they actually don't possess a Nav 6 themselves.

I did two things, one of which seemed to work (or both, I'm not sure).

I posted a very stroppy message on their Facebook page.

I tracked down the name of their MD on Linkedin and threatened to contact him.

Lo and behold instant action.

But the answer, in the end still came from here.

Hope this helps.