By the way how do you tell:
1. delayed payment
2. the due payment / the payment due was settled (i.e. it was payed, and now you don't have any debt)
3. I don't want to take advantage of your kindness.
4. Regarding the visit to the house for sale, unfortunately it cannot take place in this week, due to health problems of the owner - Otnositel'no posesheniya v dom na prodazhu, k sozhaleniu nelzya proizoidti na sleduiushee nedele iz-za bolezni vladel'tsa.
5. You are always invited in our office.