If you propose someone your services, the response you get is ответ .
If you recieve someone's opinion about the services he has already got or an estimate of a job done, this response you get is отзыв.

In your case you send a suggestion and wait for answer iether "yes,please" or "no, thank you", so you await ответ.

There is another word for feedback in Russian - обратная связь , but it is used mainly in technology.