The ignore button seems to work for you, it might help you to stop thinking about this user next time.

Obviously some users have informed that the OP has damaged the reputation of his account with a sales attempt which is not liked by many users, he is well aware of that but still doesn't feel guilty. I'm just wondering why this thread is still open, has anyone reported this thread being locked?

Even the OP is more likely to create a new account after 4 negative tags, so there's no point in telling him how to rank up to high rank. Sooner or later the OP will let this account become inactive, it's quite possible.