Dear Felix
We have just received your payment for [PRODUCT (S), ex. your order of five Magna flux compressors].
I would like you to know that I appreciate your history of prompt payment. It is customers like you who enable us, in turn, to offer you competitive prices. {MENTION WHETHER YOU WILL OFFER BONUS, ex. In appreciation, we would like to offer you a 2% discount for all invoices paid within 15 days of the invoice date.} We are pleased to have your business!
Regards
Lydia