I want to stop unknown numbers calling my iphone5

Go to recent calls, then info on that call. Use the copy feature on "Unknown Caller". Then go to Contacts, touch + to add a new contact. Use the paste feature for the following: first name, last name, company, phone number. Touch done and you will see an option to block caller. Then in Settings you can go to your Phone, Blocked, and you should see it listed alphabetically with any others you may have. I have an iPhone 5 with iOS 7.0.6. Good luck

On your iPhone, go to Settings>Phone>Blocked and add the numbers you don't want to receive phone calls from to the block list. For more details visit: How to Block Numbers on iPhone and Find Blocked Numbers on iPhone