$25 rebate from Showrime

I signed up for SHOWTIME 2 weeks ago- HOW DO I GET THE $25 FROM THEM?? IT SAYS I NEED 3 MONTHS OF BILLS FROM THEM- BY 4/15/2016 AND MUST BE POST MARKED BY 4/15/2016-I WONT HAVE 3 BILLS FROM COX BY THEN SHOWING SHOWTIME? OFFER EXPIRES12/31/2015- I JUST GOT A MAILER FROM COX THIS PAST WEEK?--HOW CAN IT ALREADY BE ALREADY EXPIRED?? PREVIOUSLY I HAD SHOWTIME WITH DIRECTV-BUT I DO NOT HAVE ANY OF THOSE BILLS? ON ANOTHER NOTE-WHAT ARE THE SHOWTIME CHANNEL NUMBERS WITH COX? PLEASE ADVISE??