Most unprofessional telesales people - Claiming to be calling from Vodafone. However it is doubtful as they were trying to sell phone contracts and had no knowledge of me existing contract arrangements.
When trying to call back - there is no answer.
Pain in the ARSE!

Very persistent.. blocked them weeks ago but they keep trying :)

Similar to Philips experience, I was abruptly hung up on while calmly explaining that I was happy with the current arrangement and don't need a new phone.

They didn't have my plan details and asked for my pin.

Person had an Indian accent.

SO ANNOYING THEY CONTINUALLY CALL ME every two days.

They call and there is no one there. Then beeps and says Goodbye. I suspect they are trying to determine real phone numbers so they can sell the data

Vodafone promotion