I am not receiving the hutch bill from the last 3-4 Month

Dear Sir,
I am not receiving the hutch bill from the last 3-4 Month and i usually make the payment without bill. Every time customer care call us to remind the due date and then the collection agency calls every second day. But how can i make the payment without knowing the break off my bill.
Why are you not sending my the bill?
This is not only in my case but one of my colleague is also facing the same problem.