An improvement to an earlier thread.
I rang vodafone for the 900 xnet mins/ unlimited texts/internet/landline calls reduced from £40 to £35 online
Explained how some mates got the tariff at half price and £50 credit. She asked for their number ( which I did not have !) I said I could get it tomorrow. She went away and within a minute said she could do it - no problems. At the end she even recapped on the deal with me.
Super deal for £17.50 !!