Unjust Billing: Charged Without Service

Rain handed over my account to easton berry for debt collection which I have fully paid. Just waiting for those attorneys to provide a paid up letter. Rain cut off services but they are still billing me for a sim card they have cut off, not to mention that the sim card is not even in a device. When you inform them of the matter(on facebook), the agents are just nonchalant and keep responding with the same thing as if they are robots. Another thing is, they keep calling asking me to make payment to them. And with that part, I am really confused.

I've used rain for a while and if you did not pay, they suspend your sim card and do not bill you, even if you stay 2 months without paying, the initial amount you owe won't increase but now it's different.