Shocking service - ZEP application

Paid for visa on 20.09.2017. I have emailed 10 times and phoned 5 times. PROMISED a call by supervisor Martha on 02.10.2017 within 72 hours. Still waiting. Called again today and fobbed off with the same excuses. Same story. I've paid TWICE for the visa to try and see whether a second attempt would reflect my payment. Each call is a 10 minute conversation where all details have to be provided from scratch (clearly no online form of capturing calls or information). Can't get any reference for calls. Can't escalate further than Martha. Call agents always say 'she's not on the floor', 'she's not here right now'. Martha - where exactly are you? Still awaiting your call.