Parking Ticket for Paid Parking

I was wondering if anyone has dealt with anything similar. I occasionally park at 1385 Larimer Street whenever I head into the office. In October, I paid to park there and didn’t realize it was a problem until I received a $104 ticket in the mail.

Looking back at my text messages, I never received a receipt when I paid through the QR code hanging in the lot. However I have proof of payment through my bank statement. I sent this proof to the Parking Revenue Recovery Services Inc. and they said it was not sufficient because I don’t have a receipt. How should I deal with this if I was never provided a receipt to begin with?