24 months cellphone contract but phone not working

I took out a 24 months cell phone contract in July 2015 and I'm paying monthly via debit order. In December started troubling me, it just switches itself off even when the battery is full. I contacted Fonechoice in January but I don't have records. They promised to send someone for collection, two weeks later I called again still no one came to collect. On the 26th Feb I called them again and I asked for their complaint resolution centre number or ombudsman details, they refused to give me but they said I must send an email to [Email Removed] of which I did. On the 3rd March I received an email apologising for the inconvenience and they promised to send someone. On Friday 4th I received a call asking for my address again and promised to pick up the phone on Monday the 7th March but up until today 15th March 2016 no one has came to collect. When I took the phone they promised to repair if it faulty or replace since I was forced to take out it's insurance. I'm still paying for it but its not working