Many members had mentioned this problem when merit system was launched. After, you have given merit to a post, if you refresh the page same number of merits are given to same user again. For instance, you give 5 merits for a post and refresh the page, he will get 5 more merits.
Though I am surprised that this is not fixed yet by the admin as it is a major bug in my opinion.
I'm sorry Mr. But I think you're mistaken. Though, you were right about the bolded part of your sentence. Its true that when you refresh the page after sending sMerit, sending sMerit will be repeated and the amount of sMerit you sent will be sent again. But, before it happens, a message box will appear first confirming that if you return to the to the page, your recently action (Sending sMerit) might be repeated. It will only repeat if you click "Continue" button and I think the OP didn't clicked it. He also didn't mentioned anything about this message box so it means that he didn't refreshed the page after sending sMerit. Maybe he just accidentally clicked the "send" button again. Because if he really refreshed the pages, the message box will appear. Though I am surprised that this is not fixed yet by the admin as it is a major bug in my opinion.
This is the message box I am talking about.
Edit. Image resized, Thanks for reminding Mr @edwardceng.