Mail with the original package and a letter saying it was rejected because of the declined CC transaction.
How long is that? We got something similar and about 8 or 10 days later a text with the case number.
The mail with the I797C took about 2 or 3 weeks. Also the letter with the online access code.
By accident we saw the text with the declined CC transaction. Knowing they wont try again I just send a new package immediately.
The note that the first one was declined took quite a while, probably 4 weeks.
Did you put in credit card payment?
We had an issue with our first mailing. It got delivered but later we learned credit card was declined thinking it was a fraudulent charge (lock box address). We sent another package with check. That worked.
Just as a possibility.