Providing one time codes to O2

[Henrique]

is it ok to provide a one time code over the phone to o2 as long as I called them? I received a one time code randomly and was concerned someone was trying to access my account. I phoned O2 by calling 202 from my mobile and they asked for the one time code. I was reluctant to provide this since the message said to never share it, not even with O2 staff. She insisted that because I called them I could share it. Is there any risk that I shared the code with the O2 operator?  

[Enlli]

O2 usually send two text messages. The first saying they are about to send the code and not to share it and the second the code itself which is usually entered on the website.

Never heard of CS wanting the code.

[Henrique]

She said it was for her to confirm it was me since I called them. She said they would never ask for the code if they call me. I called 202 from my O2 mobile though so surely there is no risk? 

[MI5]

@Henrique 

In this instance I'd say you were safe, but you should never give a website code to anyone in future.