Dispute, i made the payment transfer but buyer says they haven't received it.

A few mins later i made the trade again for the same amount, and again waited for them to confirm.

This time they opened a dispute. We have exchanged screenshots where i have proof of both payments.

But they have a new screenshot of their account and haven't received anything.

What can i do in this case? If i cancel again is there a chance i could lose both payments? I have transferred the trade once already and haven't received that money back.