Lack of service from outsurance

I submitted a windscreen claim on Monday 12 March 2018. I was then advised that National Auto Glass would contact me in order to fix my windscreen. National Auto Glass then contacted me and told me that my windscreen would be fixed in 3 to 4 working days. It has now been 2 weeks and my windscreen as not been fixed. I have been calling both Outsurance and National Auto Glass but no one has given me feedback and the crack on my windscreen is worsening. I spoke to a consultant who said they would give me feedback, but they still did not contact me. I then followed up again, but I still have not been helped.