Had my system installed 6 weeks ago and have been ...

Had my system installed 6 weeks ago and have been waiting for a technician to come as it is not working correctly. Have emailed over 4 times and have been promised that a technician will come today and yesterday to make an adjustment to our inverter but another day has passed and once again no technician. When they have got your money they seem uninterested in getting our system up and running correctly. Not happy.