Growatt Inverter SPF5000ES - not good!

Growatt Inverter SPF 5000 ES failed 3 times in 5 months. Sales company for Growatt tried and is speechless. This model inverter does not even appear on Growatt SA's web page. Trying to make contact with Growatt but receive no response, not by e-mail neither by phone (phone numbers on website seeming is not even working).