I'm looking for a short story, probably written in first person, about a writer. His writing machine (a typewriter, I think) breaks down, so he buys a replacement. Typewriters aren't sold any more, so he buys a newfangled writing machine that 'learns from the writer'. It works well at first, but then starts acting up when he types. Corrects his spelling, grammar, word placement stuff like that. At some point, he calls customer service for help, gets told that these are new machines, they don't know much about them, or something along those lines.
At the end, the character wakes up one morning, to find the writing machine writing all by itself, in his writing style, but better, and faster than he could write. The character ponders "What am I to do now?"
I'm fairly certain I read this story in a book or an anthology, not a magazine. I don't remember when I read it, but it was probably at least 5 years ago, and the story probably wasn't new then. I read the story in English. I don't think it was translated from another language.