1. When you have gotten a complaint from someone or when you need to apologize to someone whom you are unfamiliar with.2.To allow you to return to the store to continue to shop and allow you to continue to use their services.
It is to inform about how the shop treats their customer and also to inform about appointments.
2.) To show the sender that the recipient is sorry.
Such letters are necessary when someone writes to you to lodge a complaint, and you need to apologize to the person whom you do not know.
It is to apologize when a complain is lodged.
When and why are such letters necessary?It is to apologise to somebody who you are not close with or with higher authority in a formal & polite way.
-What is the writer's main concern in such a letter?It is to try to get the customer to continue patronising the store or continue using the services they provide.
When and why are such letters necessary?It is needed when something unexpected happens. They are necessary because they are to apologise for the unexpected incident.
It is to apologise and make sure the customer understands the reason of the poor service.
These letters are meant for reply apologies