NOTICE TO CUSTOMER: UNDERPAYMENT, SEND BALANCE
We have just received your payment of $[AMOUNT, ex. 5,200.24] for [PRODUCT (S) / SERVICE (S), ex. your order of five Magna flux compressors]. Thank you for your payment. Our records, however, indicate that the total billing for that invoice (#[INVOICE NUMBER]) is $[AMOUNT, ex. 5,400.24]. Please check your records to ensure that I have not made a mistake. If you find that we are correct, please be so kind as to send the remainder, $[AMOUNT, ex. 200.00], at your earliest convenience. Otherwise, please call me at XXX-XX-XX so that we may update your account accordingly.