While it’s incredibly upsetting, stuttering is so misunderstood, I wouldn’t expect someone who works in a garage to necessarily frame stuttering as a disability. Also, as you may be realizing, getting revenge isn’t going to do much to help YOU in the long run. What will help is to make “practice” calls to other businesses, use vvvoluntary stuttering, and see the results. I’ve done this hundreds of times and only sensed imatience once. This will help YOU realize that most people are kind and patient.