If this is unavoidable, then a polite second request must acknowledge the first answer and imply a reason for the repetition: “Is that what your watch says, as well?” And thanking anyone who gives an answer is a good first step.
Dear Miss Manners: I organized and paid for a family reunion. This included paying for five hotel rooms for my family, a meal at a restaurant costing $600 and a game in which I gave out envelopes with cash in them (total of $200). After the party, I also did lunches, which I paid for, totaling about $300.
Mind you, I am retired on a fixed income. I had to fly across the country, for which I paid. My family is reluctant to acknowledge or thank me.
No one except one cousin offered to pay their own way on anything. When I returned, I wrote 23 thank-you notes to them for coming. I mentioned on social media this fact, and the fact that I had received no thank-you notes from any family member. Then I got on social media and found many notes from my family condemning me, saying I was not kind, nor Christian. It broke my heart, but this is the norm from my family. I am pretty much ignored.
Is it now normal not to send any acknowledgment for a kindness given? Is common courtesy now dead?
Courtesy is not dead, Miss Manners believes, though she sometimes needs to be resuscitated when she faints on the pavement (courtesy, not Miss Manners, who pays more attention to her footing).
The situation you describe leaves several points to be cleared up, even aside from why you spent so lavishly that you imply it was a hardship.
Writing thank-you letters to your host after an entertainment is, indeed, a requirement of good manners, although the cash outlay involved is irrelevant. Writing thank-you letters to your guests for attending is not. Publicly shaming your guests for a failure to write is both rude and, as you discovered, likely to incite further rudeness.
Dear Miss Manners: At what age is it proper to add "and guest" on an invitation? (For example, wedding invitation, family function, etc.)
The question is not the age at which such a designation can properly be added — because the answer is “never” — but at what age it can be dropped. Anyone inviting small children to a party must expect the invitation to include someone to bring them, to retrieve them and to make sure, between those two events, that they do not climb the curtains. Once those functions can be accomplished unaided by adult guests, Miss Manners advises you to invite people by name.