Indian accent operator, claiming to be from Vodafone offering a discount, claimed that you won't need to do anything to get it, but will ask you to confirm your details.
Checked against the Vodafone caller list and number is not there.

Caller: Pretending to be calling from Vodafone

Female voice with Indian accent pretends to be calling from Vodafone offering me a 30% discount if I combine my mobile phone and internet plan. Asked for my Vodafone PIN number, Vodafone sent me an SMS text message with a code that I was supposed to tell this lady over the phone although the text message says "Vodafone will never ask for this code".

Caller: Call center

Indian accent saying calling from billing department and attempting to convince I owed to a service I don't subscribe to

Incoherent / muffled voice with an Indian accent attempting to convince I owed to a service I don't subscribe to