Poor workmanship and expertise. No after service support.

I got them to install a Deye battery, inverter and panels. A year later when attempting to add more batteries, I found out from Deye SA that the wrong battery was installed, which could cause the system to blow up. Called the installer, he accepted that they put in the wrong battery (HV), he promised to replace the battery last week Wednesday, then he said there was not stock and said he’ll get it this past Monday. He then said that he will install yesterday or today (Saturday) but he now ignores all calls and messages. Unable to get hold of him. I sitting with a system that could potentially blow up, even after they had provided an electrical certificate.