I later came to know that asking someone for merit is prohibited.
You see, you would have known that had you been anything other than a bounty hunter who doesn't really care about discussion here. It's been talked about endlessly that merit begging is frowned upon, especially via PM. The last thread I posted in about that was only within the last 3 days I think. There's no excuse that you didn't know that your action would result in a negative.
In addition, your warning is going to be ineffective. Why? Because, just like you, people who beg for merit tend not to read anything in Meta and won't see it. You yourself would have missed such a warning--in fact, you DID miss everything that would have warned you not to beg for merits. It's your fault, so own up to it.