Phone was sent in for screen repair and its taking ages

Phone was booked in for a screen repair it is way past the 21 days i had to follow up via phone since i got no feedback on progress i have called numerous times , emailed , even resorted to Facebook to no avail. i keep getting promises about it being escalated and will be called in 2- 24 hours .. the time i got a agent willing to help mentioned its at CTDI a 3rd party repair center !!! and the phone has failed quality testing 3 times i fear my phone has been destroyed