Earned 6 months free Pro, installation fails

Avast Free Antivirus / Premium Security
1

Hi, I refered a friend to install Avast and got the reward of 6monts free Avast Pro… but if I install it simply states it’s a 30 day trial version, no license at all…
how do I get my 6 months Pro, or is this a cheap trick by avast?

2

https://www.avast.com/recommendation-terms-and-conditions