Roaming abroad not working

I’m having a problem with data roaming right now (in Spain). Also German O2, but on the FP1. It was working fine until this morning, when it suddenly disconnected, and now I can’t get it to connect again. It’s possible that I’ve used up my 50MB data package, but normally I then get an SMS from O2 offering to buy more data and I just do that. However, I’m not getting that SMS either. WiFi and Phone network are working perfectly. Any ideas?