Matic sent to unsupported Uphold wallet

Hi all. I sent 1074 Matic from Nexo to my Uphold Matic wallet using the Polygon network, which was wrong. (Should have been Eth network). Uphold are saying that they can retrieve them for me…for $500. They can obviously be recovered, so does anyone know how to do this? I could just wait and see if Uphold begins to support the Polygon network. This happened with Coinbase, and customers with the same issue had their tokens recovered. Any thoughts or help would be greatly appreciated. Thank you.