How can I prove that I provided a service?

Hello,

I run a service based business where I offer site creation, marketing on social media and coaching 1-on-1 with my clients.

My clients purchase from my website by using their cards, and my payment processor is Stripe.

I was wondering, if someone calls their bank and says that I scammed them, or didn't provide the service, how could I possibly win the chargeback?

What evidence could I present?

Thanks for reading, and an up vote is always helpful, and could help someone in my same situation.