Attempting to Upgrade AVG Antivirus with paid-for Internet Security on Catalina

Hello Dan. 
Thank you for contacting AVG Community Support.
We have a specialized billing team, who'll give better clarity regarding this concern.
Please use the below link to contact them :
https://support.avg.com/support_sales?l=en
Thank you.

Good morning,
I wonder if you can help me.  I'm having tremendous difficulty in trying to upgrade from the free version of AVG anti-virus to upgrade and include AVG Internet Security upon clicking upgrade, selecting a subscription option and clicking Continue.
A loading payment screen is displayed but appears to consistently fail to get out of its loading state.

Many thanks

Hello Dan. 
Thank you for contacting AVG Community Support.
We have a specialized billing team, who'll give better clarity regarding this concern.
Please use the below link to contact them :
https://support.avg.com/support_sales?l=en
Thank you.