Can I use Votel's reviews and case studies to build credibility for my new agency?

No. Do not use anything from Votel in your marketing. Use your own information and your own brand.

Credibility comes after your first client. Whether you start that client on a trial or on a performance basis, for example by running a database reactivation campaign, use their results as your case study (before, they had zero; after, they had ten extra appointments) and use it everywhere. Your second client gives you a better story, and you build it up one client at a time.

Taking card payments through Stripe also looks much more credible and professional than sending someone a PayPal link.