Totally useless customer service

Truly useless customer service. My 5kWh battery was swelling and my installer returned it to Sunsynk for warranty replacement, and said it's previously taken around a month - not great but I can live with it. That was in January (7 months ago!), and I still don't have a replacement, and my installer and I have been unable to even get an answer as to what the holdup is. The customer liason (Chantelle) simply doesn't answer emails, and when I've tried asking on the online support channel, they tell me the job number is incorrect but seem unable to actually help. My installer has gone all the way up to the CEO and still not been able to get an answer.