Credit card payment scam?

I got a call from someone claiming that they have mistakenly made payment towards my CC. I checked my card statement and it has indeed been credited by ~40k. I asked him how he got my number, he said he got it from his relationship manager. I called customer care and they suggested a procedure where the money be credited back to the source. But I could not go to the bank today.

He is saying, since the payment is done through SLPE app (never heard of it), it will cause an issue. So he is asking for direct payment.

I talked to him and he seems from a poor background.

Please suggest how to proceed.