Twice I've undercounted when paying in, once was only by £20 but the second was £100. If I'd used the self service till I wonder if the person checking the amount would think 'they've paid in £100 more than they've said -  I'm having that'.

But what if it's the other way round, I pay in £500 and put £500 on the paying in slip but the cashier miscounts and says I only paid in £400, what comeback would I have, how could I prove I actually paid in £500 ?
 

Given the degree of shit that would kick off if this happened with any sort of regularity, I assume they have two staff working alongside each other on inputting deposits.

You complain, they count it again. And you hope that they find the missing money this time.

Or I go to an actual cashier, they count the money in front of me and it goes straight into my account.

Once I used an ATM and it swallowed my card, heard it drop into some sort of container. Went inside and they told me they couldn't do anything and to come back the following day. The next day they said they couldn't find my card in the machine and would have to cancel it and issue a new one. So where'd the card go ?

Whatever the financial equivalent of Narnia is?

You can only get there if you're not looking for it.

I'd go to an actual cashier but, you know, queues. I'm usually in and out before the first person in the queue's got anywhere, never mind the fourth or fifth. And there's also that horrid human interaction stuff too, bleugh.

Mrs.D was a teller for about a year. The pay and benefits were terrible (they made sure everybody stayed part time so there were no benefits), and she was under constant pressure to sell 'products' (credit cards, insurance) to people on pensions and welfare. This was for the most profitable and uncompetitive industry in the country.