downloaded avast premier by mistake.can i swap

I feel so stupid. I downloaded Av premier for 3 years but did it for windows instead of mac.
Have emailed support and got a ticket two days ago but nothing more. I still want the product but I presume I need to get a refund and start again. I asked them could I just swap for the Mac one as I can’t use the one I downloaded anyway.
I am a complete numpty I know to do this but can anyone advise me what to do. I can’t see how I am going to rectify this if they don’t contact me.
Thanks for any help
Mary