OnlyModel connects you with managements and creators. The guarantee comes from the seller you buy from, not from OnlyModel.
OnlyModel is a marketplace. We help managements and creators find buyers and handle the introduction, we don't provide the guarantee ourselves.
Every management that lists a creator can offer its own guarantee, for example a refund window if the creator cancels or never responds. That's agreed directly between you and that management, before or at the time of purchase. Different managements offer different terms.
When a creator lists herself directly, without a management behind her, there is no guarantee. You arrange any terms directly with her. You can always see on a profile whether it was listed by a management or by the creator herself.
Profiles marked OF verified have gone through an identity and account check before they appear here, so you're dealing with a real, reachable person, not a placeholder.
Before you buy, ask the management what guarantee they offer. After payment you receive the contact and can settle the details directly with them.