Service not delivered

I had placed an order with Vumatel on the 31st of July and it was supposed to be installed in the first week of August but no one from Vuma came so I called the call centre to report my problem and I was told the matter would be escalated I later on received news from them that my installation would take place on the 31st of August at 10:30 after I had called for a follow up. STILL no one came on that date & when I called to report the matter one of their call centre consultants dropped the phone on me and when I called them again I was told to rate the call, how can I rate a call where the consultant didn't even listen to my problem and didn't even help me ?