Stop trying to contact them. Please tell us that you have
not revealed the identity of the driver.
You have been contacted as the “hirer”. They have no idea who was driving. Even if they had sent you a Notice to Hirer (NtH), you would not be liable as I have yet to see
any PPC correctly comply with the requirements of PoFA in order to transfer liability from the driver to the hirer.
Have Wise sent you a copy of the NtH or the NtK? Did you send them a Subject Access Request (SAR) or was this just a phone call? Any phone calls are not worth the paper they aren’t written on. Email, with or without attachments, is your best form of comms.
Had you sent Wise an SAR they would have been required to respond within 30 days otherwise face sanctions from the ICO.
Wise were required to comply with the strict requirements of PoFA paras 13 and 14. As mentioned, I have yet to see any unregulated private parking company comply fully with those requirements. Have a read of it yourself here:
https://www.legislation.gov.uk/ukpga/2012/9/schedule/4/enactedNot one PPC ever complies with the requirements of PoFA 13(2).
A PCN when in a hire car or leased vehicle is a “golden ticket” as long as the hirer does not reveal the drivers identity. As long as you have not revealed the identity of the driver, stop trying to communicate with them now.