Cox changed my SAP settings during a system reboot which caused me to lose sound on 2 channels

This Cox error caused a service call

Did the Cox rep you spoke with seem at all skeptical about your assertion of how the change to your SAP setting occurred?  Putting that aside, did they not tell you that you can change your SAP setting yourself?  How to do it will depend on the kind of receiver you have, but it's a setting you can easily change.  Did a tech actually come to your house to change your SAP setting?  If yes, how much did Cox charge you for doing that?

wander around settings/audio, you might fix your problem!