Just Eat - Poor customer service

Last night I made an order to my mums address. She was aware it was coming. Somebody pressed the buzzer, she answered and asked who it was- no answer from the mystery person. She allowed entry and pressed the button to let them in. Nobody came up the stairs to her flat to deliver the order. She was unable to go downstairs due to disability. I had a missed call, which I tried to return within 5 mins but just east doesn't allow it to go through. I knew it was unjust eat number because there is a recorded message saying that. The order said delivered- it was not delivered to my mum. I tried to speak to customer service agents- none of them gave me a reason WHY the order said delivered but it wasn't and none of them could say why I wasn't being given refund. One of them tried to insinuate I was lying and said "my story" had "inconsistencies". I asked to speak to a team leader and they said no. I received an email from team leader called ross which said;

"i've looked into this further for you, and after reviewing your account, it's not possible to offer you any refund or account credit compensation.
Just so you're aware, we won't be able to overturn this decision if you contact us again about this order. Although I realise this may not be the outcome you were hoping for, since there is nothing else we can do, we'll close this case and no further action will be taken on future replies."

They do not allow you to reply and I asked many times for an explanation. I Also asked to speak to the team leader and was told no that I had a reply and its final. I was not given an email address or anywhere I could complain about the poor customer service I received. Multiple copy and pasted canned responses and no actual dialogue. They write a lot of words but don't actually say anything and will not give any reason or explanation. There is also nowhere to complain about their customer service or above a team leader.

not had a reply, still waiting