It is not surprising that you are banned, because fixing the results/outcomes of sports events is a criminal offense in most countries. Even if someone manages to earn something from the information you provide, sooner or later they will suffer the same fate as you.

However, I think that your tactic is completely unrelated to fixed matches - it is an old trick that works in such a way that you supposedly have confidential information and give it away for free - but in fact it is about trying to convince the naive that you have good information. Those who win will give you 50% in the hope that you will give them more "fixed events", and those who lose will not complain because they got something for free.

It's a win-win situation, but only for you because you don't have to invest anything, and you can earn a lot, of course if you're lucky.