I’ve not personally experienced the same issue, but rather than speaking to customer support, perhaps speak direct to Sonos Sales instead… here is a link to contact them:

https://support.sonos.com/s/global-sales-help

Hope you get the matter sorted.

Yes - Sonos has had my returned speaker for over two weeks and there has been no refund. I’ve called twice this week, sitting on hold with their diabolical hold music I swear that’s meant to get rid of me, only to finally talk to some poor CSR who just says finance is processing it and I should see it in a day or two. Both representatives told me they’d email me confirmations of the  process, neither did. I’m super concerned about this and looking into next steps with the credit card company and how to possibly report them as a badly-performing business. I can’t believe how many people on Sonos’ own community blog are unhappy - really unhappy - with them.

It has been almost 1.5 months now. Sonos processed a partial refund after multiple follow ups. I returned 5 speakers in total and they only processed a refund for 4 of the 5 despite them all being sent back at the same time. It's really concerning as there are clear breakdowns in their internal processes. It's really frustrating as I'm still waiting for them to figure out what happened while the money and products are both sitting with Sonos. Are there no consequences for a large company like Sonos to be holding onto money owed to me  plus the returned products? 

I have similar issues. Sonos service is beyond horrible and borderline fraud. I am still waiting for my approx. 1500 dollar refund. 

You’re always best to contact Sonos Sales for refunds. Here is the link to contact them and their opening hours:

https://support.sonos.com/s/global-sales-help

I'd advise going through your credit card company if you bought via a card, then leave them to deal with Sonos.