It was a very large bill

and not one we were expecting at all.
The Senior Cat's mobile phone "plan" is supposed to cost him $20 a month. The bill was for $122. 
Something was not right. I looked at the second page of the bill - where the items are detailed. That looked really strange. 
The Senior Cat had no idea what to do about it so I searched on line and sent a message to his provider.
Message back. They cannot deal with me for "privacy" reasons. 
I told them I have Power of Attorney. They want to see it. I had to get it scanned and sent. Done.
I then get a message asking for yet more details. Sent.
Then I get a message that the bill is correct. I send a message back saying it isn't. This is a $20 a month plan and he hasn't changed anything.
Another message back saying that "data" must have been turned on.
I tell them it has not been turned on by him. He has no idea how to turn it on - neither have I. Middle Cat doesn't know either. We look at the bill again. 
Middle Cat takes the phone back to the provider's shop  in a nearby shopping centre. It was taken there several weeks ago when there was a small problem with it. The "data" charges start  on the day she did that. Yes. The shop assistant turned "data" on. There was no reason to do this. The phone is used simply as a phone - the Senior Cat uses it as a safety precaution when out and to talk to Brother Cat and the Black Cat . He has no idea how to do anything else and does not wish to learn.
Meanwhile I had sent another message to the provider telling them that this was done without the Senior Cat's knowledge or consent. The provider is responsible for the bill, not the Senior Cat. 
There is a text message for the Senior Cat. Fortunately Middle Cat is with him at the time and knows how to get to the text message and send one back. No, please don't try and talk to him - phone his eldest child on the landline to sort it out.
Ooh...I get the Complaints Manager calling me - and at the time they said he would. No, he didn't admit they were liable in as many words. Yes, he did agree to waive the charges.
The billing pattern was such that they knew the "data" should not be showing up.
The  interesting thing though is this, if the Senior Cat had been paying by "direct debit" he would not have seen the bill until after he had paid it - and by then it would have been much harder to argue the case. Maybe he has a point about the dangers of direct debit after all.