Terrible service

Faulty business line was reported on the 5th Jan. 2 days turnaround promised. It is now 10 days later and multiple daily calls and still no working line. Call was escalated twice and apparently closed a few times and a technician was on site but must have been invisible. No technician not feedback and huge loss of business. Every time we talk to someone else and then they want to insist a technician has been out to fix it but acknowledge a fault on the line. I want the highest person possible to sort this out now.