Suspicious phone call "UK Research" SCAM????

[#1]

Had several calls recently from an indian chap, asking "probing" questions about my phone line.  The missus has answered the calls previously, and todl them to ring back, they rang this evening, and he kept asking questions about my phone line providor, naturally I didn't give anything away, after much asking, he said he from a company called "UK Research", he then aked if I had a BT phone line again, I then asked what they wanted this information for, they said they would not use this information, so I replied that it did not matter if I witheld it, and then put the phone down.
Anyone else who is no longer getting their services from BT got similar calls?

[#2]

Hi there,
I've never had one of those calls myself, but I know a few people who have left BT and got a phone call not long after in the same sort of vein.
The best thing to do for these, and all these types of unwanted sales or research calls, is to register with the Telephone Preference Service, and tell the caller you're registered.
It's very effective in getting rid of these callers.

[#3]

The other thing I do, bearing in mind a lot of these calls originate outside the UK (especially if, like me you are already TPS-registered) is to use caller display (free from BT) and if the incoming call is "International" say nothing at all when you answer.
A real human being, such as a friend calling from abroad, will very quickly say "hello" or similar, call centres mostly hang up or enter an automated spiel - which is when I hang up! 

[#4]

I like to put it on speakerphone and then carry on working while they try to communicate with me. It's such a crap phone that they can't really hear me and it takes them ages to realise that I'm only interested in wasting the company's time and money. I had one guy today who called me up and hung up quite quickly but very rudely. So I returned the call and found out that it was about car insurance. I managed to give them enough of a lead for them to agree to phone me back and I managed to waste another 15 minutes of their time. I felt a slight pang of guilt about the Ferarri bit.