Help! Someone is using this realvnc app to control my iphone

Someone is using this app to have access to my phone and he has already scammed me out of quite a bit of money and is continuing to try to get sensitive information from My iphone and I've tried to disconnect him from My iphone. I changed my banking information but I don't know what else to do but he still has access to my phone because the orange dot light is on on my iPhone. Does anybody know what I can do to disconnect permanently from this fraudulent person?