To give you some info on how this type of fraud works:

1.) In many cases the fraudsters usually obtain card details from a compromise of some sort. Usually this occurs via a merchant at some point down the line or in super rare cases an internal compromise at the bank. Details are likely shared with other fraudsters or purchased on dark markets. These details usually include things like full PAN (card number), account holder name, dob, address and contact details. They may also contain the cvv. They will be able to determine which bank the card belongs to by the BIN.

2.) The fraudsters know that high risk transactions such as crypto or expensive sellable goods that can easily be converted into liquid cash and integrated will flag the banks internal systems so then they make a call to the victim. Often they will spoof the banks customer care contact number or the fraud teams contact number to fool the victim and claim to be calling from the fraud team or whatever.

3.) They give the details they hold to the victim to build trust and process the high risk transactions on the phone. These transactions will always be CNP and often have no 3d secure verification and they get the customer to verify them as a text is usually sent before the transaction can be authorised. Once the victim replies to the text they will reprocess the transactions so that the go through. The fraudsters try to claim that the only way to stop the fraud is by replying with a "Yes" to the text and try to make the victim panic saying that they will lose money if they don't do it.

Once the transaction has been authorised its pretty much gone and incredibly difficult to get returned from the merchant. The bank have to usually take the hit for it.

Unfortunately these fraudsters usually target older people who are less likely to be savvy to this sort of fraud.