This has happened to me twice - I show up for a scheduled walk/drop-in visit and there is a friend/family member in the home that the owner hasn't told me about. I explain who I am and why I'm there. They acknowledge that they expected me to show up but then they say that I'm not needed. Has this happened to anyone else? How do you handle it?
Given that the customer has not officially cancelled the scheduled visits, they're not entitled to any refund. Now, how this works with the Rover card, I have no idea because you have to perform the service and document it via Rover card in order to be paid. I would document it in the system, putting it in as a cancellation, but that no refund is due.
You need to be paid for going there. If customers think they can just tell you on the spot that you're not needed, then it will continue to happen.
I would contact the owner right away and Rover as well. When you agree to go into someone's home to care for their pets while they are away, you are taking a huge responsibility, to their pets but also to their homes. What if these people were robbers, resentful exes, adult children that are not really allowed in the home without the owner present, you never know. See what they tell you and take it from there.