Revision rounds
Most companies build in one or more rounds of revisions. That means after they show you the first mockups (“initial concepts”), you give feedback, they adjust accordingly. If you don’t like a design, you can use those revision rounds to steer things toward something you do like.
Feedback / design brief
There’s usually a design brief at the start where you explain what styles, colors, layouts, inspirations you prefer. If that’s clear, there’s more chance the designer gets close to what you want. If feedback is vague, it’s harder to hit the mark.
Refund / money-back guarantee clauses
Some companies do offer refunds (full or partial) under certain conditions, especially if dissatisfaction occurs early on. But many also have terms that limit refunds once certain steps are past (like approval of initial design, or delivery of final files).