Do they know you are deaf? Some people would take it as an insult if they don't know why you wrote down the order.
I used to work at a convenience store. I have trouble understanding people sometimes especially when I can't pronounce some of the cigarette brands. There was one black lady who asked for certain brand of cigarette. I couldn't really understand her very well so i asked her to repeat . She got mad at me and asked me if I had a problem with her (I've met her several times before, but you know people ask for cigarette all day long so I can't remember everyone). I guess she took it as an insult that I asked her to repeat several times . I had to explain to her that I am hard of hearing and it takes me awhile to get used to different people's speech. And that sometimes I don't know how to pronounce some of the cigarettes so I can't figure out which is which.
people usually point it out for me so that's how I managed. What I really needed was someone who would pull me aside in a quiet time and help me pronounce some of these cigerettes.