Original: If you have received any notices from us regarding non-payment, please contact us immediately so that we can come to some form of payment arrangement.
Simplified: If you have received any news from us about non-payment, please contact us immediately so that we can come to some sort of payment agreement.
Simplified: If you have received any notices from us regarding non-payment, please contact us immediately so that we can come to an arrangement for payment.
Simplified: If you have received any notices from us about the non-payment, please contact us quickly so that we can reach some form of payment arrangement.