I bought a refurbished s4 mini about 5 weeks ago. I had a s3 mini which the police have got with the same number. My s3 was great. I got a sum only tariff and have sent about 5 texts and used 2 minutes. Internet okay. I get no service or not registered on network. On the status it says I'm disconnected and no network state. I have no other phone to try the sum card in but gave tried other sums on other networks in my phone and they work fine!!!!. I've made 9 calls and been on online chat umpteen times. Is it time to sack 02 off???