Uc mail bug

I had 1386 uc and i was collected from the mail 2700uc but it appears that I only have 3486 uc, there are 600 uc that did not count in my acount The previous month i get only 400 uc from mail 200uc of them due to dublicated rewards so only 200uc is supposed to be deducted not 600uc I collocted them from mail by read & calim all This video explained i had 2700uc in the mail and the photo explained i had 1386 before i collect the rewards I won 2 rooms in 2-12 and 29-12 for 400uc and i get 400uc in the mail at 8 jan . So no dublicated rewards i had before