I work for one of the big 5 banks and handle online fraud and a whole lot more, heres a few things you might be able to add to help beef up security and reduce chargebacks.
Verified by Visa, or Mastercard securecode, I help people with online shopping fraud in my job and provide Verified by visa to many clients for online shopping because it is creating a Pin or code for you to use with online purchases.
As a merchant can you contact your merchant solutions and bank and inquire about enforcing this for all transactions.
https://www.visa.ca/en_CArun-your-bu...d-by-visa.html
https://www.mastercard.ca/en-ca/merc...ecurecode.html
Hope this may help to all Vendors.
Nick