@FloridaCharlie
thinking this over, I suspect a big part of your surprise and upset (over being surprised) is that at home, you have really excellent medical insurance, so generally just show your card & it's handled. Seems what you had to go through with filing insurance claims due to your wife's injury on the ship was a process that was very very new to you. So many of us have had to go through similar rounds so it seems pretty much standard.
We had a doctor that we really liked, years ago; he used to file insurance claims for us. It got so time cnsuming, that he realized he was paying an extra staff person to handle our insurance claims. Going forward, he would provide receipts that we could use to file, but we had to file ourselves.
Had you understood the process, and not been surprised, you'd have been able to submit the paperwork to Medicare first, etc. But, not knowing, you submitted to the travel insurance first, then after the "normal" 4-5 week turnaround time, finally found out you had inadvertently skipped the first step. Frustrating, but if you research you'll see that all secondary policies work the same way.
Next time, you'll know.
Regards,
Mary