Webcomicsapp is currently #1,841,755 on Alexa. For reference, Hiveworks is #526,547, Tapas is #21,251, Webtoons is #2,129, and Wattpad is #707.
Webcomicsapp has 195,000 ratings on the Google Play store, compared to 61,000 for Tapas (why so low), 1,678,000 for Webtoons, and 4,100,000 for Wattpad.
These stats show that Webcomics is nowhere near the level of other webcomic sites or apps; if we assume they have something like 200,000 daily daily users on the app (a massive stretch considering the Alexa score), that's over 1.2% of the entire readerbase that subscribed to you in one day.
So, I don't know why Webcomics is faking their stats, but it certainly is easy to find the proof that they're wrong. It makes me much more hesitant to work with that site in the future, knowing that they are doing something like this.