Also to the OP, I get your frustration but I think you should move on ,threatening to sue for $30 is ridiculous, as is spending $3000 to drag their name through the mud.. Also typing in ALL CAPS A LOT LIKE THIS IS CONSIDERED SHOUTING so if you want to be taken seriously, you'll cut that out. Finally while it would be nice for an exchange to have all the procedures in place to catch unauthorized account access in real time, the reality is that according to their terms of use or whatever the agreement is called, it's up to an account holder to ensure confidentiality of their login credentials. Assuming you used Windows, I would suggest reinstalling your operating system to clear it of any suspected malware and use a safer browser like Chrome or Firefox, plus various security software , otherwise Linux, though the latter has a bit of a learning curve.
Can't you do 2fa via the web as well? Or is it limited to smartphones + yubikeys?