This is because you are not here enough to learn all the rules and quirks of this place, @crypto.piotr. Signing up for things is only Step One. The whole steem ecosystem is very complex and you need to monitor everything you do here.

If you are only coming in a few times a month, you will not have enough time to figure things out fully. I totally object to the term "vote stealing" in this case, since you gave your permission without knowing what you were doing.

I use @steemdunk for autovoting. I have been very happy with them for 1.5 years. Maybe you can give them a look, but read their terms and conditions if you do.