help/advice re disconnected landline.

I am in need of some advice from the community. I will try to cut the story short but I had a new broadband cable fitted on Sat 22nd March due a faulty wire after several days of no broadband. Thankfully I had no issues with my landline as I am an emergency contact for my father who has stage 4 cancer and mobile coverage in my area is extremely poor. On Sunday 23rd I was informed that my father had been trying to contact me Saturday night but could not get through. I checked my landline, it was dead. On checking the outside cable box it became apparent that the engineers who fitted the new broadband cable disconnected the phone line, tied the wire in a knot and shoved it back in the box! It is unclear why they did this and worst of all did not tell us.

I have called virgin media almost daily, at times waiting over an hour to get through. Each time explaining the situation about my father. So far this week engineers have failed to turn up for appointments on Mon 24th, Tuesday 25th , Wed 26th  & Friday 28th . I called to complain again on Fri 28th and was assured engineers will be here on Sat 29th between 8 and 12. The Virgin Media rep said he would call me at midday to ensure everything went as planned. No engineer arrived and no phone call. That's 5 no shows within a week! I sent an official complaint earlier in the week with no reply as yet. I have lost several days pay waiting for no shows, wasted hours on the phone explaining the urgency of the landline. I wish to escalate this further but each time I call I just get another call centre member of staff with another appointment date and another no show. How can I escalate this? Thank you.