Possible to upgrade from Antivirus Plus to Total Internet Security?

Hello,

I purchased Antivirus Plus a couple of days ago for 1 device 3 year subscription.

Now I am thinking I want to have Total Internet Security.

Is there a way to upgrade Antivirus Plus to Total Internet Security instead of purchasing a new product and losing my current 3 years?

I did a Google and found an article about upgrading from Antivirus 2016 to Total Security 2016 and it added the TIS years onto AV 2016 but as this was 5 years ago I have no idea if the same thing would happen if I buy TIS today and activate it.