Usually when I call a place to ask about something like that I find if I go "Yeah my name's such-and-such and I had the thingamajig and I was wondering if it was ready." I'll usually get asked to repeat everything I just said at least once. So anymore I just tell them that I'm calling to check on whatever it is and wait for them to get ready and to be asked for my info. I would imagine a lot of people do the same thing but the way they word it makes them sound like a ditz. Or they're just having a brain fart.
When I worked in a quick lube I had several regulars that would expect me to remember their full name off the top of my head. We had a standard greeting, ask what they'd like and if they've ever had the car in before. I was careful to word it just like that "Have you ever had THIS CAR in before?" Not something they might mistake for "have YOU been here before?" Still more often than not we'd punch in the plate number into the computer and nothing would come up. I'd go and ask if they changed their plates or something (we were near the state line so it wasn't uncommon) and I'd usually get "Oh no I just bought that car, first time I ever brought it in. But I already have an account here." Then I would try to explain that our system doesn't have accounts, the records in the computer go by individual cars and we punch in the plate #, in a vain attempt to avoid this situation in the future. They look me straight in the eye annoyed and butthurt and tell me that I should remember them since they come in all the time. Never mind they have no idea what my name is, that they're one of 30 people that day, or that "all the time" actually means 2 or three times a year.