Ellies repair centre took 17 days to realize they are not allowed to work on my Mecer inverter

The Mecer inverter we bought from Ellies Hatfield in December 2017 has an earth problem and I handed it in at Ellies Hatfield on the 24th of April 2018. They said repairs can take up to 3 weeks. Last week, Vincent from Ellies Hatfield, told me that the inverter was sent to Mustek, Midrand for repairs. Since it is a Mecer inverter, the technicians from Ellies are not allowed to work on this inverter and it had to be sent to Mustek. I got the Mustek job-card number from Vincent and then found out from Mustek that they only received the inverter from Ellies on the 11th of May 2018 - 17 days after I handed it in at Ellies Hatfield. Vincent showed me the documents where our inverter was sent to the Ellies repair centre on the afternoon of 24 April 2018 so they did everything correctly at the Hatfield branch. The problem I have is that it took the Ellies technicians /repair centre 17 days to realize they are not allowed to repair my inverter and only then sent it to Mustek. Co-incidently, we were without power in our area from Saturday evening, the 19th of May 2018 at midnight until Monday, 21 May 2018 just before 5pm. I bought groceries on the 16th of May 2018 and since our fridge and freezer was without electricity for approximately 40 hours, I had to throw away all the meat I bought for the month. We laid out an enormous amount of money on the solar system because we know our area is often without power. Since I handed the inverter in at Ellies (31 days ago), our area has been without electricity on 8 different occasions. I hold Ellies responsible for the loss of my groceries. If the repairs centre had sent my inverter to Mustek the moment they received it, I would have had my inverter back long ago and would not have suffered any losses