You did something wrong. Traveling first class with a second class ticket? Wrong or missing check in? Traveling in the wrong direction? Forgetting to check in or out with a discount season ticket leads to € 12 (€20 x 0,6),

Here some information.

Traveling in the wrong direction results in a correction fee of 50 euro. So it's one of the other 2 options.

Was your card checked by a conducteur? Then it's likely for traveling first class with a second class ticket. 

Edit, another option for a correction fee of 20 euro is having activated Samenreiskorting without travelling with someone with a subscription. 

And there have been cases in which a correction fee was charged for no reason, in those cases the conducteur could have made a mistake. 

Believe me, i didnt do nothing wrong. Every month i going to Eindhoven twice. And every time i stand right by the door , because is it close to Helmond. I hava never had a problem until today.

Did you had a ticket check (as such very rare) during this trip?

IF yes-did conductor tell anything about being wrong?

DO you leave at some Helm. stop where there no barriers, but only masts for check out? YOu may have forgotten this.

In case of high unexpected fines anyone says its not their fault. But sad to say, this ultimate very complicated system here in NL has so many options to do things wrong-even when you do not realise it at all- that this forum is full of complaints like yours.

You should have received a mail stating the reason for the correction fee. If you think this is not correct, contact customer service, either by phone, chat, Twitter of Facebook.