Strange one...

[Nathanx]

Hi. When I call my friends number I get a recorded message from the department for work and pensions, pensions department... Other friends with his number don't have any problem, I thought I had the wrong number for him to begin with but even calling him straight back after him calling me this happens 🤔

[BandOfBrothers]

That's certainly weird @Nathanx 

I would suggest to delete the number from your contacts app and any sign of it in recents etc and go into something similar to the phones app via settings , apps, phone app. Location and clear the cache.

This should purge all remnants of the number for your phone and then without adding the number to your contacts app call the number.