I doubt that this is related to rate limits, as you would usually receive an error at that point, and the rate limits are described in the documentation and reflected in the code headers. I strongly suspect the automated algorithms that work to avoid problematic content are in play here. Again, since I don’t know your app and cannot access your case I cannot tell what the specific issue was.
Our rules are clearly documented, but we also need to adapt to circumstances when apps behave in an irregular manner. Many of the systems for detecting this are automatic, due to the volumes of traffic we deal with. I take issue with your statement that Twitter “allows [follower collections] for a fee” - I’ve been working on the platform for nearly three years and this is not the case - we have a strong stance on the auto-follow and follow-back apps and have consistently said that this is not allowed. If you would like to report an app you believe is violating our policies, you can easily do so via the platform support forms.
I’m sorry you’re waiting, but we need to look at tickets individually and in order, and sometimes we can’t always do that as fast as we would like. Hopefully we can work to resolve this with you very soon.