Hello Wesley,
Thank you for contacting us with your concern. I wish I could help you but, this community deals with the technical queries regarding AVG Windows products and AVG Android product support is provided through email only.
Please submit your query to our android support team from this webpage http://support.avg.com/SupportArticleView?urlname=How-to-contact-support-through-the-Mobile-Contact-Form and they will get back you at the earliest with a resolution.
I sent myself an invitation to use AVG tuneup to my mobile (Android 6) and when I entered the invitation code, I got the answer that the code was invalid. I sent it to myself this morning and entered it on my phone around noon. Is there a validation period regarding this code I might have missed (e.g. works only for 6 hours)
Wesley, Please note that this Community deals mainly with the technical queries regarding AVG Windows products. AVG Android support is provided through email only. Please click on the following link (http://avgclick.me/AVGtechnical) and fill out your details, select as Android then the name of AVG Program that you installed in your mobile and in description please completely explain about your issue and finally click on Email option. Also when filling out your details choose Yes for the Question "Are you currently using any paid/trial AVG products?" and click on Email option. The AVG mobile team will reply back to you via email with a resolution.
AVG Guru