IPVanish and other VPN Services

I am based in the UK and an using an Android Kodi set top box. I have recently installed IP Vanish for anti-virus and security reasons, howeverI notice that this has halved my broadband speed. When I disable IPVanish my throughput is approx 26 Meg, with IP vanish enable it is around 13 meg. I expected some slowdown due to the rerouting of traffic through the VPN gateway server and then to my Cable Modem, but this seems excessive. I have tweaked my IP configuration to the “use the best server” option but this still does not help. Currently my VPN server is in my local Surrey area just a few miles away from my home, so I cannot see this distance as causing the issue. This obviously has an effect on my streaming operations, with movies sometimes freezing and having to be restarted. I was wondering if anyone else has seen this issue with IPVanish and knows how to work around it, or is using another VPN service that gives better performance than this?

Thanks and Regards