2019 Update 3c

SOLVED

Hi.  I think I  made a huge mistake.  I tried to update to 2019 3c in order to do the year end update, but I clicked on the 2020 update instead.  And now I'm not able to go back to 2019, I havent done any of my year end procedures yet.  I have tried to phone for support, but unfortunately the lines are too busy, and it keeps cutting off.  Would you be able to assist?