Humble/polite speech

Hello

What is the proper way to reply to someone who is being humble?

For example this:

Person A says: ''I hope you meet some nice people''
Person B says: ''I already met nice people and one of them is you''
Then person A says ''But, I'm just one person, it's no big deal''
Person B says: ''It's still something''
Then person A says: ''I'm not a great person''
And person B says: ''There may still be something of value''

What I wonder is how to reply to someone who is using humble speech. For example: ''I'm not a good person'', ''I'm not beautiful/handsome at all'', ''It's just an insignificant gift'', etc.

Btw, person A is the Japanese person, whereas person B is me, the non-Japanese person.
What do you think about my replies to person A?

Thank you for reading.

Person A says: ''I hope you meet some nice people''
Person B says: ''I already met nice people and one of them is you''　貴方（あなた）に会えたことは光栄（こうえい）です。
Then person A says ''But, I'm just one person, it's no big deal''
Person B says: ''It's still something''
Then person A says: ''I'm not a great person''
And person B says: ''There may still be something of value''そんなに謙遜（けんそん）されては
困ります。or　されなくても。

Hi ay, thank you very much for your response and the Japanese translation!

Sorry, I forgot to mention that the conversation between person A and person B (me) was all in Japanese.
(I typed the conversation between person A and person B in English, because I thought that not everyone who might read this, would understand it in Japanese)

Ok, here is how our conversation went:

Person A: 素晴らしい人と出会えるといいですね。
Person B: もうやった
Person A: なにを？やったの？
Person B: はい、あなた
Person A: 私はたいした人間じゃないですよ。
Person B: それはまだ何かあります
Person A: それは何ですか？私は素晴らしい人間ではありません。
Person B: それでも何か意味があるかもしれない。
Person A: ありがと。
Person B: どういたしまして
Person A: 疲れてませんか？
Person B: 大丈夫です。あなたは？
Person A: 少し疲れました。
Person B: 私が何か言ったの？
Person A: あなたのせいじゃありませんよ。
Person B: 分かりました
Person A: はい、大丈夫です

I wonder if my replies weren't quite in place.
Any tips and advices will be highly appreciated.
Thank you for reading.

I guess "Mou yatta" might have sounded a bit blunt. The verb "yaru/yarimasu" is a casual version of "suru/shimasu," and can sound a bit rough - if you wanted to say "I already did" in the sense of "I already met someone great," then a better way to put it would be "Mou aimashita." Even saying "Mou shimashita" would have elicited the answer "What did you do?" from him. It is better to repeat the verb itself ("aimashita") rather than literally say "I did."

"Sore ha mada nani ka arimasu" - is that supposed to mean "There is still something to it"? That might have sounded a bit strange to him.

It could have gone something like this:

A:素晴らしい人と出会えるといいですね。
B:もう会いましたよ。
A:だれですか？
B:あなたです。
A:私はたいした人間じゃないですよ。
B:そんなことありません。私にとっては素晴らしい人です。