My Avast! interface kept bugging me to renew my Internet Security (paid) program. It said that if I renewed early that I wouldn’t lose any days. They lied. I was cheated out of two days by renewing two days early. I wrote to the contact address and said that if I didn’t get a new licence that I would demand a full refund. Very politely of course. 
Still waiting for a reply… Anybody else have any experience with this? I couldn’t find anything on the fora.
Did you add the licence file that you were e-mailed, as it has always added the extra days for me
Not sure where you contacted, but you can also use the https://support.avast.com/ system to submit a ticket. Or check the F.A.Qs if there is anything related, but you should get the days back.
If you didn’t receive reply, please send me a message with the email address you registered to your renewed license.
This discrepancy was probably caused by registering another email address than the original one.