Banks
I love it when the bank contacts me and then asks me to confirm my details.
"and how do I know you aren't a scammer trying to get my details, you called me, you know who I am!"
Then they ask you to call them back but won't tell you why!!!
"if this is about my credit card being overdrawn by $5, I'll fix it when I care, I'm not going to bother calling back."
Because I'm always going to contact my bank for the reason "I don't know".
Tossers.