How do I stop my mobile number being witheld?

[Nik73]

How do I stop my mobile number being witheld? I have show called ID turned on (iPhone 5s) but when I've tried several times to enter a radio competition, I get an automated message saying we can't accept calls from callers who withhold their number! I've spoken to Vodafone about it before and they didn't come up with a solution. It's very frustrating 😕 Also I have to go into the store as I have not received my new SIM card which was sent out to me a week ago 😡 I think equipment like this should be sent as special delivery or preferably couriered rather than 2nd class post!!

[BandOfBrothers]

Hi

When you call your contacts or input a number to the dialing pad and ring it etc is your number also showing up the same ?

Have you tried a reset. 

On the iPhone hold down the Sleep/Wake Button and Home button together until the Apple Logo shows. Then On seeing this Apple Logo release both buttons ,and the iPhone will reset , which has been known to clear most glitches.

and

Settings -> General-> Reset -> Reset Network Settings.