I love my cell phone, but I can live without it. I don't get a lot of calls on it. Most people call me at home. husband is the one who calls me the most on my cell, but a few friends might call. Most of my friends have my cell number and I have theirs, but unless it's urgent, we usually just leave a message on their home number or send an email. I like texting....it's great for sending husband a list of a few things to get on his way home. It's useful for saving time, but if I send 10/20 texts a month, it's a lot. I suppose if I worked out of the home 40+ hours, I'd probably use it a lot more, but since I work from home, I don't use it that often. I have been on the phone at a checkout, when it was important, but I acknowledge the person that is checking me out and if I can't get off the phone while they are checking me out, I usually apologize. I've been on the checkout with Missy's neurologist, when I was waiting all day for the call. She just happened to call then and I would rather have taken the call then have to wait another 12 to 24 hours for her to call me back. Know what I mean??
However, speaking loudly and rudely is ridiculous and obnoxious.
I have to tell you, when I was much younger, I dated this guy who had one of the first cell phones, you know the big phone with the big battery and atenna? I was mortified when we'd go to diner and his phone would ring. EVERYONE wouldn stop and look at us. Now, it seems so commonplace.
I was in a restaraunt, recently, when the dad was with his family. Through the entire dinner, he was on the phone several times. Now, my husband is on-call frequently with his business, but if he was getting that many phone calls during dinner, he would have gone out to the car to deal with it. I didn't get the impression that this was on-call business. Not only was this rude to his family, but it was rude to the other diners. He wasn't speaking softly either. I found it to be quite obnoxious.
I worked in retail for years and years. I always ran after people who left their stuff behind, but I think I might have done the same in your case.
I have been in stores where I've left things behind and know I lingered around a little. I was quite ticked that I wasn't given the same courtesy, and I wasn't on the phone or being rude.