You should try calling them and seeing if they have received it but haven't processed yet. They were very nice about it when I called for one of my letters earlier in the summer.
When I called in July, they told me they had my letter and were in the process of processing it...it came up on LSAC.org later that night.
Haha, well, if you want some humor....my recommender (who is my BOSS!)has been lying to me for two months about having written the rec. He apparently hasn't started it yet.