Extremely disgruntled customer

I am extremely dissatisfied at the service that I have been receiving from Supersonic. I have been a customer of theirs since the time they started and recently have been receiving the worst service ever. I recently upgraded my fiber line and the speed of the line is extremely slow. I reported this to the office on Monday and went into the offices yesterday. A technician was booked to come and see me this morning at 9. No-one has arrived and when you phone the landline, it states that the telephone number is not available at the moment. Supersonic catch a wake up. Your service delivery is pathetic. I am paying for a service that I am not getting and this is wasting my time and money.