Unless there's a problem with the avionics, and a simple cord repair is required, you may be able to do it yourself, depending on the location, by removing one end of the cable and using shrink-wrap, of most avionics shops should be able to do the cable replacement.

There are also dedicated headset repair shops that just do aviation headsets, such as KC Headsets (https://kcheadsets.com/aviation-head...-services.html), that do work on Lightspeed, Bose, etc.