Keep doing everything exactly as you have been. (i.e. shut up and accept the late payment, each and every month, month in, month out, year after year.) All th

Keep doing everything exactly as you have been. (i.e. shut up and accept the late payment, each and every month, month in, month out, year after year.) All the other suggestions in this thread are totally wrong. if you want, I'll renegotiate with you. Their new payment due date is 30 days later. Bam. They're now paying early, instead of paying late. All without talking to them. All on your end. Its just psychology. It's all in how you look at it.