Did you solve this? I am suffering of the same problem!
Tagging on to a topic that is almost 2 1/2 years old isn't advised, much would have changed, both in the program and background services.
Either give more details on exactly what you have tried and a screenshot where possible (with personal/confidential details obscured) only then can we try to point you in the right direction.
Did you check the link given by Asyn - Sales - Orders and Renewals FAQ -
https://www.avast.com/faq.php?article=AVKB24#artTitle.
Or check out this information - Sales change order details wrong email address given, etc.
- Submit a support ticket
https://support.avast.com/en-ww/contact/sales in your case select the Billing, payment, or license issues option - and then the I have a different billing or license issue and click Next and follow.
This will ask for an order ID, which you won't have - then enter 00000000 and give as much information that you can to help identify it.