Welcome to Vodafone Community
I have given up on the Suresignal, only use is as a paperweight. It's unofficial but I think Vodafone have given up as well, they are focused on promoting wifi calling instead. So I now have an iphone 6, wifi calling enabled, problem solved.
I'm sorry to hear you've had problems using your Sure Signal @RobX, we've certainly not given up on these and would be happy to look into getting yours back up and running.
Our Troubleshooting guide can help with a number of common issues and if your problem's not covered, follow the steps under the 'Issue not listed' heading and we'll be happy to take a closer look into this for you 😊