money-back guarantee; satisfaction guarantee
A commercial term for a promise that a customer can get a refund or replacement if not satisfied with a product or service.
This product comes with a 30-day satisfaction guarantee.
Since there's a money-back guarantee, you can try it without worry.
返金保証 specifically means 'money-back guarantee', while 満足保証 is broader, covering satisfaction in general, which may include refunds, exchanges, or other remedies.
Compound of 満足 (satisfaction) and 保証 (guarantee). A straightforward modern commercial term.