I received an RMA email minutes after chat with the Sonos agent.  The link to initiate the process failed to complete. 

A follow-up chat about the problem led to an escalation to the 'returns team'.  I was told I would receive a reply within 24-48 hrs. 

Almost a week later and I'm still waiting... 

My problem is compounded by having to use the chat support (due to a speech impediment which makes phone support almost impossible).

I sort of expected better practical support from Sonos.