This Radio 4 programme reports on the way that Virgin have been treating an 86 year old couple (it's the first feature.)
https://www.bbc.co.uk/programmes/m002v0z1
They lost their TV (and phone/broadband) back in January, were told that it would take until July to fix it and told that they must carry on paying their bill in full.
When they said that they needed to be able to call for medical help, they were lent a mobile phone, but were under strict instructions to only use it for 111 or 999, so could not keep in touch with family or friends!!
After Radio 4 became involved, it was fixed within a day and the bill payments were refunded.
The programme also said that 71% of people who complain to the body responsible for seeing that they treat people properly win their case and that Ofcom have already fined them for not looking after vulnerable customers properly.