Adt Security
SMS pest. Incorrect Billing

I am being sent SMS every 2 days to check an alarm which is no longer linked to ADT. which was signed for by previous tenant who left 2 mnths ago.
We have no written contract or signed agreement with them.
We have called to inform them every week for 2 months and they still send us SMS to check the alarm and the account which is not for us.

we consider this to be harassment.