I renewed my subscription 'the moment' Renaissance became available, and it has the date of 5th of November, so you renewed way to early to get Renaissance.
Now I don't doubt that you saw that "Add Renaissance to subscription" message. From 24th to 30th of September was the week of the Renaissance Previews (by Donald X.), where you could play the revealed cards online. That version of the pogram has of course to know about the Renaissance cards, and because the program contains a variable with the name of the latest expansion, of course it is possible that that variable was incorrectly set to "Renaissance".
The good news no. 1 is that I'm 99.9% sure you did not pay for Renaissance, though I'll ask to check. The good news no. 2 is that if you now try to buy something, it should ask you again if you want to add Renaissance (for real now), and, as usual, you will only be billed the difference to what you already own, so that would be Renaissance only and should come out as $3-4 until 26th of Sept., 2019.
I'm sorry for the confusion caused by the wrong message.