I unlocked no advertisement, MailTab still advertises!!

Dudes. I bought "no advertisements". Nevertheless MailTab annoys me once a week with new features to buy. What I spend money for? If I need to go pro or something then dont offer In-App-Buy which says "no advertisements" because then I have to spend money twice. So what am I supposed to do to use your obviously not trustable app in a serious way without being annoyed?

Steve Pony about MailTab for Gmail - Email Client, v6.4