I've been having awful trouble. Have an iPhone 5C and I'm currently in Malta. For the first 24 hours I had no service and I was constantly turning on and off airplane mode and finally got service. However last time I had that problem in Croatia my data worked too once I got service, now however although I have service here my mobile data isn't working, I've tried changing the APN, MMSC and all that but nothing. Anyone have a better suggestion?
Yes it's very annoying and I don't know why it hasn't been fixed at this stage.
Unfortunately given that you have tried other fixes and they did not work all I can suggest is that you contact 48 support in case they can offer more//better advice.
Hope this helps.