The safest way to deal with an incoming call which might just be genuine - for instance, if they're asking you to confirm a reference number - is to consider that they already know what the information is, and who you are, otherwise they wouldn't be ringing.
In that case, agree with them that you'll give (say) 2/3 letters or numbers and make them confirm the others.
Any errors, then put the phone down.
If it's a genuine call, it serves two purposes - it proves to you that they say who they are, and proves to them that they haven't mis-dialed the wrong person.
Same if your address is requested - give them partial information, but insist they give you the rest.
If they refuse, or are unable to complete, cut 'em off.