020 8106 7407 Negative Who called me from this phone number?

Unrecognised number. to me Called twice and left text message saying. it was a 'free call alert from O2. To disable dial 901 press * then option 5 and then option 5 again'. I haven't done this as it seems dodgy.

I missed the first call, picked up the second and assumed it was spam, and they instantly rung back right after to which I heard a foreign accent telling me they were from O2 and was informing me of a new change to my SIM. I was at work so arranged a call back later, I have just got off the phone from them telling me they were sending out new SIM cards to help with signal for free and they needed my email. I was hesitant so to get my ‘trust’ they send out a code that only apparently ‘they could send’ and I wasn’t to share the code, it was just used to get trust. I still didn’t share my email and they began to get more irate and I questioned why this was the first I’d heard of it and would like to wait until tomorrow, and that was when they said my SIM would become blocked as they’d started the process. I have since blocked their number.

Suspected Scammers. Didn't answer as they using the usual "London" code from India. They need to get a life or Karma will bite them eventually for trying to scam people.

Put phone down but kept calling back. Blocked number.

Said they were from Tesco and that they are blocking SIM cards and upgrading their systems and sending new SIM cards out, at this point I hung up . They rang back quickly and then another 3 times after I hung up each time . I blocked the number

Had a call saying they were from Tesco and that they are blocking SIM cards and upgrading there systems and sending new SIM cards out. I questioned it and she got very irate telling me she will block my smart right now so I can’t use it.

They are going to block my o2 SIM and send me a replacement. Also used 02075517435