Hey ! I’ve been working as an IT technician for 3 years now, in a job where I have to take 10-30 calls a day, at first it was extremely daunting but the best decision I could have made, putting myself into a situation where I am uncomfortable has improved my speech in all genres. I am much more confident and slower speaking with friends and relatives and engage myself into conversations much more. As a stutter best decision you can make. You will sometimes get the odd impatient customer on the line but as long as you go at a pace you’re comfortable with no one can complain. Put yourself into the situation and it will do wonders, good luck