Jim,
That's it. TrackMaster = Axcis Information Network in Mountain View California. I was under the impression they billed by use if you have the Pay-as-you-go plan, but perhaps they now save it up and bill weekly.
You can double-check that they got the amounts right and that you agree with everything by cross-checking your usage by looking at your downloads in your TrackMaster Account here:
https://www.trackmaster.com/cgi-bin/my_acct_entry.cgi then click on View My Downloads. You can see, by date, the RDSS card files which RDSS downloaded for you.
Ted