This site's own materials are unusually direct about this specific inconsistency: the brand's homepage says the window runs from your purchase date, while its returns page instructs you to confirm the delivery date through carrier tracking instead.
Two different brand pages describe two different starting points for the same 60-day guarantee — purchase date on one page, delivery date (via carrier tracking) on another — a genuine internal inconsistency, not a third-party claim.
Email support with "Refund Request" in the subject line before you order, and ask them to confirm in writing which date starts your specific 60-day clock, per this site's own direct recommendation.
Confirm your guarantee start date in writing before you order.
See Jellyblue Pricing