Dangerous two-digit code entry requirement

I've been having a problem dialing international mobile numbers in the UK. I can call landlines in the UK no problem. But when I call a mobile, I get a message that comes on saying "to complete this call, please dial 34" (for example). It's always the same message with the two numbers at the end changing with each new call. This is dangerous because when I'm driving and tell my phone to place a call, I have to take my eyes off the road and look down at my phone and enter the numbers manually. I don't want this. I called customer service and the person said it was a government mandate and T-Mobile couldn't remove it. Is this true? Has anyone else managed to remove this dangerous requirement?