No Sound Or Microphone Working On Battery Doorbell Plus

So ring contacted me after I bought a new unit & was dissatisfied from the purchase. They swapped it out a similar priced unit that solved most of the issues. However I always had terrible wind noise on it. Supposedly they updated the software on it & it was a little better after a few weeks. Then it got increasingly quieter over the next few months & now you cannot use it as an intercom. Neither sound or microphone work & I no longer get a response from the email team who originally contacted me. It's less than 6 months old - ring battery doorbell plus. Now unusable. Have done all the usual, re-boot etc. Signal fine, video feed fine. Does not work with audio either way – mic or speaker. Have tested on 2 phones & one computer – same results. Anyone got any ideas?