You can only get certain member benefits when they're active. For example, this past week members have been able to get double the rewards on daily assignments. You can't get a free chest on dungeons or free training point buyback right now because those rewards aren't active at this moment in time. Usually every weekend (or longer if the rewards are a daily thing, like the daily assignment benefit from this past week) a new reward is active for members, and they chance weekly. So you'll just have to wait until the training point buyback and free second chance chest rewards become active in the future.