Quell Free - Paid to remove ads but ads still present.

Hi! First, love Quell! I downloaded and installed Quell free from Google Play, and shortly thereafter paid to remove the ads. However, the ads are still there. When I go into the section where it says you can pay to remove ads and hit that again, it says I already have that version. Clicking on the "details" button that pops up with that message gets me a black screen and a message that Google Play is not responding. Any ideas about what I can do to remedy this? Thanks!