Can't make a call unless it's connected to wifi

I've just arrived in the UK,bought a lebara sim and paid for 30gb. I followed the instructions to install it in my unlocked phone, checked the coverage map and it should be good indoors and out. But I haven't been able to use my phone outside my hotel (it's connected to the hotel wifi). I've turned the wifi off, and still won't connect to the voda phone network. I was hoping to use it as a hotspot, or at least make phone calls or send Whatsapp messages. But nothing works.

DeborahS4 is it just data you're having issue with or are calls and texts not working either?