Cut off my up to date electricity with no reason

my account is up to date but to my surprise my electricity was cut off today 22.05.2015 . City of Tshwane send the letter claiming that my accont isdue but to my suprise my Payment of account is due on 2015/05/27. Last month payment went through pick n pay paypoint. I just wondering \what wrong with city of tshwane accounts?""""