Terrible after sales

OHHEX installed solar panels for me and they did a good job. After sales however hasn't been a horrid affair. They promised me a free clean for my panels which never happened. I paid extra for an earth breaker which was supposed to be initially installed with the panels and they just did not pitch up for 2 appointments. I even paid in advance for "annual solar maintenance and system functionality testing" which was never done. 4 months later, I am still waiting for a refund.