I just did 2 tests and they worked. Google voice and my regular number.

I know you know to check the rest but...

Does your phone provider have any SMS filtering?

Do you have any SMS / filtering on your phone even, can you check your block list? Make sure you did not accidentally mare the last text they sent you as spam. I did that once.

Did you reach out to them on social media instead of just opening a ticket?

Good luck.

-Dave