Unilateral changes to an alleged contract

Yesterday I received a letter from ADT in my post box, dated 25/09/2015. It refers to \Billing for excessive responses""; failing which I will assume that there is; in fact; no agreement or contract in place; and I will consider any alleged arrangements or agreements with ADT to be null and void.<br> <br> I look forward to receiving some cooperation this time; so that I can investigate whether the alleged agreement/contract allows for such a unilateral change; and if so;whether I wish to continue making use of ADT's services."""