Sadie, and Frustration with Medicare enrollment

First of all, let me tell you about Sadie's recent problem:  She has been her usual active self, but for more than a week she's been vomiting violently.  It seems as though she was doing it more and more each day.  Nine times out of ten, it would be phlegm, but sometimes there was actual food involved.  I cleaned up four vomit-spots on the rugs yesterday.  As soon as she was done upchucking, she was ready to go for a walk or play Frisbee.  Mighty peculiar.  Since she seemed otherwise healthy, I kept waiting to see if she would get better on her own.  
Today we finally took her to the vet, who felt her throat, , opened her mouth wide and looked in, took her temperature, and pronounced her healthy.  He thinks she has scratched her trachea, or perhaps has an infection somewhere in her respiratory system, that's making her cough and gag.  So he gave her a shot to keep her from vomiting, just in case; and antibiotics for any infection she might have.  Oh, and that will be $100, please.  I also had him give Sadie a kennel cough shot so if we go on vacation for any length of time, we could board her there.   
The head vet at Oak Grove Animal Clinic was out front as I was paying my bill.  Cliff and I were among his first customers, back around 1970.  One time we had him repair an umbilical hernia on a Holstein calf I was bottle-feeding.  Cliff and I held the calf down on the office floor, and Doc Findley stitched him up.  We were all such kids then.  
Anyhow, Doc greeted me  with, "Well hello, Donna; how are you?  Do you still milk those Jersey cows?"  
Good grief, I haven't seen the man for at least twenty years, and he remembers me that well?  Of course I told him about my years of not milking, and how I missed the little Jerseys so much I got Bonnie.    


Now, on to my rant.  Cliff will be 65 in June.  He doesn't want to sign up for social security yet, but as we understand it, he has to sign up for Medicare by age 65.  I am so confused, and I just want to talk to a real person, not a robot on the other end; I tried dealing with the robot lady, but she kept getting the social security number wrong when she repeated it back to me.  I have tried vainly all morning to accomplish this, and gotten nowhere.  It's so confusing!  He could apply for Social Security online, but that isn't what he needs.  And I'm not sure whether he's supposed to get Medicare A or D or what; he has good insurance where he works, so he doesn't need any of it.  I even tried calling a local social security office, figuring I could talk to someone there who would answer my questions.  Nope.  The phone rang and rang every time I called it, and nobody answered.  
Grrrr.