AppStore rejection because of scraping or using unofficial API

I am currently making an app using Tinder API. It's very similar to those auto-liker apps that leverage Tinder API as well.

My app was rejected on the ground that the user is not presented Terms of Use Agreement before accepting to send login info to Facebook for use of Tinder token.

Now that is fine, but Apple also called me and said that "There are rules not written in guidelines, and we do not accept apps that use unofficial APIs and scrapes websites that you do not own."

I checked the guidelines, and only things written there are that

1. Do not use unofficial API - I interpret as non documented iOS API.

2. Do not scrape Apple websites

Furthermore, there are dozens of Tinder auto-liker type apps, and yet more apps that scrape third party websites.

Why is the Apple review team telling me those things?

Has anyone else ever heard from the AppStore review team that:

• We can only use "Official" APIs
• We cannot scrape third party websites
• There are rejection rules that are not written in the guidelines.

Any feedback is appreciated.

EDIT

• The point here is that is there an unofficial non-written rejection guidelines. I believe that is a gray issue since it can be grounds for lawsuits and I want to get experiences of other developers if they have received similar explanation over voice calls.