When calling Sonos Tech Support there’s an option to have STS call you back. I’ve used the option with success. Here are a few things you need to know:

• After being placed in the “Hold Queue” you’ll be subjected  to a string of announcements.
• You’ll have to listen for the opportunity to leave your number and later receive a call from STS
• If you miss the opportunity while listening to the announcements not to worry the cycle will repeat and once again give you the opportunity to leave your number for a call back *
• Once you hear the offer to leave your number “Press 1” (or whatever the IVR tells you)  on your phone and you’ll be prompted to use the number from which you are calling from or another. ^
• If you’re like me you may have your phone set to automatically reject calls that are not in your contacts folder.
• Don’t add STS to your contacts folder because the number STS calls back on may be random.
• Go to settings on your phone and turn off “auto-reject calls not in your contact list”. **
• Also make sure you have “Call Waiting” or Incoming Call Notification”  feature turned on so you can switch over if on an unimportant call.
• If you miss the call just call STS again and either stay on hold; or opt to use the call back option as before
• Be sure to keep your phone near and the ringer turned on.

 * The cycle is in continuous loop if you miss the 1st, 2nd, 3rd or more opportunities to use the call back option

 ^ IVR = Interactive Voice Response

 ** Don’t forget to turn this feature on again when done conversing with STS