Hello there and thank you for contacting justanswer today!My name is ***** ***** I will try my best to assist you with your problem.Are you a new customer to Vodafone? Has the SIM card which you have put into your phone and applied £20 to been activated? Have you only just received the SIM card?If you are a new customer and your SIM card is new, it needs to be activated before it can be used. SIM cards are never sent to a customer activated and there should be instructions with the pack that tells you how to activate it.The best thing you can do regardless of the situation is contact Vodafone support as they will be able to tell instantly where the problem is, and ultimately if it is a situation where you need your SIM card to be activated or are having service issues then they can fix these problems for you on their end.Please use one of the following numbers to contact them:From a Vodafone mobile - 191Other UK phone - 03333040191You could also speak to online support if you would rather. You can do so by going to the following link: http://www.vodafone.co.uk/contact-us/ : and clicking the following options:>Personal>Pay as you go>Looking for something else?>Can't find what you're looking for?The live chat button is then shown.I will personally try my best to help you if you are struggling with any of my steps above, and I wish I could speak to Vodafone for you, but this is something which you will need to do, as they will ask specific account and personal information to fix any issues with your service with them.I hope I have been helpful, and again if you require any futher information or details please do not hesitate to reply to me below before rating my service, so that I can make sure that you are fully satisfied with it!Best of luck, and please let me know once this problem is resolved!Thanks,James.