In a word: bureaucracy.
Let's say my name is Mary Sue Balfour. Apparently when registering for grad school on some form my name got switched to "Mary Balfour Balfour." Now the registrar's office cannot be convinced that that is not my name. We have a go round every academic term where they say my tuition hasn't been paid, when it turns out that Mary Balfour Balfour's tuition hasn't been paid, but Mary Sue Balfour (who has the same ID number, birthday, address and phone number) has paid her tuition.
Every quarter, they request that I provide either A) a copy of the court document where I legally changed my name from Mary Balfour Balfour to Mary Sue Balfour or B) two pictures IDs; one with my "old name," Mary Balfour Balfour, and one with my "new name," Mary Sue Balfour. However since my name never was legally Mary Balfour Balfour, I can't provide any legal documentation that my name was changed to Mary Sue. Eventually some supervisor sighs and agrees to credit Mary Sue Balfour's tuition to Mary Balfour Balfour's tuition but I really need to fill out the legal paperwork.
Unfortunately this office releases the tax document that shows how much tuition I've paid during the year. This time I came armed with that and showed that all the information from the university's W-2 under the name "Mary Sue" was the same for "Mary Balfour." The supervisor visibly recoiled and said she couldn't look at anything with a social security number on it!
And no, it makes absolutely no difference to them that there is only one Balfour (much less a Mary Balfour) associated with the university and according to all the other systems, including payroll, HR and IT, her middle name is Sue, not Balfour.
I had a similar issue with my Council Tax. This is a tax you pay here for which is based on your address. If you are the only adult living in the property, you get a 25% discount.
So, I was paying my tax, claiming my discount, no problems. A friend of mine moved in temporarily as a lodger , so, being a law abiding person, I notified the council that I was no longer eligible for the 25% discount.
It took them about 7 tries to get the new bill right (they kept trying to backdate it to the start of the year, then they worked it our manually but faileld to account for the fact that you pay over 20 months not 12, so 6 months in ou've paid more than half, etc)
Then my friend moved out, so I informed them, confirmed I was once again entitled to the 35% discount, and worked out what I owed and set up a new payment of my own.
I then started to get letters saying I wasn't eligibble for the discount.
I said yes, I was. Just me in the house.
They asked "So when did Mr M Lastname move out?
?? - who is Mr M Lastname?"
Them - we have two people living at the property Mr M Lastname and Ms M Lastname (except they had my full name for both)
Me - "I think you have a typo. There is only one person here. Me. There has never been any Mr Lastname. If you look at the names, it's the same name - I think someone must have entered Mr instead of Ms into your system"
Them Yes, I see. So if you could just tell us when Mr Lastname moved out.
(About 9 months after this conversation took place I moved house. I'd had about 12 further bills in the mean time, all of them wrong in different ways. At one point they told me they owed me about £200, and I was very tempted to take it, but I couldn't. I think they'd got it wrong by about £10 in my favour at the time I moved out, and I did decide to leave it at that - I decided I'd probably spent that much on phone calls and stamps trying to sort it out.)