Poptelecom, please stay away

Angryson

My 72 year old father has had an utter nightmare with these people who care little about customers and customer service. They have treated him poorly and then charged him close to £500 for cancelling his contract.
I tried to intervene but they did not want to know. They just wanted his cash.
My Dad is a full time carer for my Mum who has Dementia and his phone is a lifeline for him.
Due to an admin error between PopTelecom and his bank he missed a payment, one month after taking a contract. He made the error of taking up a contract after being pressured by the sales team after a cold call. He was told he could get out of the contract at anytime.
Having missed one payment he was cut-off, without warning! No letters, no calls and the first he knew was when in an emergency he needed to call the doctors and his phone was dead.
When he phoned them from his mobile to report a fault he was told he was cut-off for missed payments.
He phoned to resolve the issue but was cut-off. No-one attempted to call him back.
After telling me I tried to intervene but after calling them they were pretty insistent and not very understanding. They also explained if he wanted to get out of his contract he could but would need to pay crippling fees. I was pretty appalled at how bolshy they were. They said it was his own fault and should have read his terms and conditions in his Welcome pack!
As a 24 hr carer my Dad hardly has time to eat never mind go through laborious t and c's with a fine toothcomb!
I asked them to call my Dad and resolve the situation. They called him but he had obviously lost all good will. My Dad decided to cancel the contract and they charged him approx. £500 and wished him well!
£500 that two pensioners, one a carer and one with mixed Dementia could seriously do with. PopTelecom are not the kind of company anyone should sign up with, ever.
I'd like to know how my Dad stands on getting his money back?
Any advice appreciated.
Mr. Lewis can you help?