Merits are not just given based on the weeks or months that members have sent in the forum, but based on their quality posts. Once a member posts valuable information to the forum, their posts will receive merits from different members of the forum, so if you want your account to be receiving merit, you need to improve and start posting interesting information to the forum, and from that, you will see that merits will start flowing into your account. So the secret that behind an account should always be receiving merit is through quality posts, so someone's valuable contribution is what can make someone be able to rank up his or her account.