Merry Christmas SMS

Hi, Every year this time one gets the normal message saying do you mind if we take your monthly bill off because and the reason is always the same, holidays, my clients would tell me to take my business elsewhere, but anyway. This year it was slightly different. The sms goes like this, Dear valued customer, due to the upcoming holidays CellC will be debiting your account on the 21st December, for queries, contact the call center. So you are now saying you will do it, is this legal that you are now not asking for permission, Maybe in some small print you have you are in charge. Anyway have a merry xmas to you CellC and maybe next time be a little nicer, at the end of the day it still is my money no matter how small it is