BT - scam marketting calls - have you had one ?

[jpaul]

Have you had scam BT marketting telephone calls ?

The full history - Aunt had a landline call from someone trying to sell additional Mobile BT services, she currently has just basic adsl broadband and a telephone line from them.
At her request, they 'authenticated' themselves by providing details from her most recent bill.
She let them continue their marketting spiel for a while, but politely terminated the call saying she did not need these additional services.

We subsequently contacted BT to try and determine if the call was genuine.
BT said they do not make marketting calls, and it was a scam call, this assertion is obviously worrying to her.
BT did not provide a theory on how the caller had access to bill information, or, say what was is the correct way to confirm if a caller is genuinely from BT.

 

[jpaul]

I subsequently looked for online checklists to follow to enable older relatives to verify legitimacy of callers and could not find anything significant,
(albeit) an American site had the following scam I had never seen before

Immediate Questions — A somewhat new scam begins with a call asking, “Can you hear me?” or “Are you the homeowner?” Any question that can elicit a “yes” response can be used in this situation. The purpose of the call is to obtain an affirmative response to the question so that the response can be recorded and used in various ways. In many cases, the scammer already has personal information and desires to have your voice recording to approve changes or credit charges. If you dispute the transaction, the scammer has your recorded “approval.” If someone begins a telephone conversation with a question, hang up or ask questions in response. Do not affirm any information on the telephone unless you are absolutely sure who is calling.