MD Inc Debt collection system sucks

This company has very bad manners when it comes to sending you the bill. They send you a rude sms telling you you have an amount outstanding and if you dont pay it they will hand you over. but they do not have the courtesy of sending you the invoice before sending the rude sms. I have requested an invoice three times, and not received one. Just more threatening sms's. Fix your system MD Inc. !