I'm trying to setup Smartcall for my sim only mobile. It asks me to login from my main account. But seems to only work with my Virgin home account, which is free calls evening and weekend, whereas my mobile is unlimited calls. I work somewhere where the mobile signal is rubbish, but work has good WiFi. So wanted to use smartcall with my unlimited mobile calls. I don't want to sign up where I'll get hit with call charges with an unlimited mobile.
Sorry to hear you're having some issues with Smartcall. I'm afraid the Smartcall app will use your landline tariff and not the mobile tariff. There's no way around this as it's the way the app is designed.
I'm sorry I couldn't help more. Let me know if you have any further queries.