I'm Sergei Tokmakov, California attorney (Bar #279869). Auto-renewal traps are widespread in SaaS. Three angles to explore:
(1) Did the vendor provide the contractually required pre-renewal notice? Many MSAs require the vendor to notify the customer 60-90 days before renewal. Failure to do so can void the renewal. (2) Was your missed notice a result of email/contact info changes the vendor failed to track? Notice sent to a person who left the company may not constitute proper notice. (3) Is the unilateral $48k for unused service a "penalty" rather than liquidated damages? CA disfavors penalties.
Practically, most vendors will negotiate a 30-50% exit settlement when challenged. A demand letter citing the relevant defenses on attorney letterhead at $575 flat is often the most cost-effective path. Informational only.