It is from the Sunnah that you should reciprocate the one who does you a favour.
The Messenger of Allaah (SAW) has enjoined that when he said:
[Recorded by Imaam Abu Dawood in his Mudnad and graded authentic by Sheikh al-Albaanee (RH)].
“Reciprocation depends on the situation. With some people, reciprocation may be by giving him something similar to what he gave you, or more.
Source: Sharh Riyaad as-Saaliheen, vol. 4, p. 29.
Do good to people when they do good to you. If you can't do them any favor, say JAZAAKALLAAHU KHAYRAN (May Allah reward you with something good).