Tesco Mobile Scam?

[Ilovehatecleaning]

In the past two days I have received a few texts from Tesco Mobile saying welcome.
Thing is, I don't have a Tesco Mobile.
I have tried to contact them but it's only free if you have a Tesco Mobile. So I tried the online chat. I would much rather a chat to someone. Anyway, they said that they would investigate but only if I confirmed the PIN number they had just sent me (I had given them by phone number). When I asked her why, she said she wouldn't explain and told me she needed the PIN.
Does this sound right?
I asked her a few times to call and she said she couldn't.

Forgot to say that I didn't carry the online conversation on

I'm with Tesco always need a pin to do anything, but you might be better going into the phone shop within one of their supermarkets. I've never had any issues and they're always happy to help/

I have Tesco mobile and if I need to log in to my account to look at anything they do send me a PIN number so it sounds like it is routine to have to have one.