Not receiving my dog tag (Daily Mission)

Well 2 days ago I only had one letter left and I did the mission that day and receive my letter that I needed but I notice that it wasn't there so I thought I just finish filling in my double R's for the word Fire and two days later (Right now) I have already finish every letter except for the R in Cross and today I receive and R but it didn't show up. So I should have gotten my dog tag finish two days ago... but I end up finishing two more missions that wasn't needed and still havent gotten it done.