Product failure and warranty

I have been using 2 x MKS inverters for the past 3 years and I'm off grid. Bought a new MKS2 5kw because it has a few new features that are not in the original MKS. Installed the new one and sold the 2 old ones. Was working fine for a week. Then I bought 6 solar panels and added them to the inverter. Was all running fine for an hour or so then inverter went pop a displyed error code. Took it back to the supplier who then took it to Mecer. They said it would be repaired. 2 weeks went by and no word on the inverter. Then on a Friday I was told that a technician was busy with it. By late Friday they said it wouldn't be finished on Friday and that it would be ready Monday morning. Monday morning came and went and was told that it would be ready Tuesday morning. Tuesday morning came and went and was told that the inverter had been repaired but that upon testing they found another fault. And won't get it that day. I am off grid and have no power for more than 2 weeks. What kind of service/support is Mecer giving? The product failed within a week of being purchased and now I must have a "repaired" unit? Why can't they just give give me a replacement? Was going to buy a second inverter and use in parallel with this one but with this kind of backup and service I think I'll be looking elsewhere. Very unfortunate, I've been dealing with Mecer/Mustek for more than a decade and never experienced these issues before. Please Get your support back to a level it was years ago.