Talk:Finland/@comment-213.255.164.48-20170318063114/@comment-91.152.194.201-20170318081832

It should be easy to do via Sonera application https://play.google.com/store/apps/details?id=fi.sonera.refill.android&hl=en

, at list exists separate "button" for order "Surf Time 7 days unlimited".

Or via WEb : https://www.sonera.fi/kauppa/puheliittymat/prepaid/prepaid+lataus/

But I'm not quite sure if you can do this via SMS if you have balance on card already.