I applied for a studentship, after the interview I was told I was selected. References were taken and all was ok. At the last moment just weeks before starting I was told I don't quialify for studentship due to my nationality. They are happy if I pay for PhD (home student fee) but they won't accept me as home student for studentship. What disappoints me is acceptance and then refusal. Can i do something about this?

Will they pay anything? Sometimes, they require non-EU/UK students to pay the difference between home and overseas fees.
What is your nationality?

i got resident status in UK but of course not Uk/EU citizen. nope they wount pay nothing now. i feel i shall end up paying for PhD from my pocket. *mad* hehehe

you can wait three years and then they will pay.

its already three years :)

Then they are being mean.

it has to be 3 years as a tax payer, or tax payer's dependent, so 3 years at Uni doesn't count

You need to have been ordinarily resident in the UK for 3 continuous years for reasons other than full time education. The people who offered you a place should have checked your status earlier. Problems arising from inefficiency in university administration departments are all too common. Unless you supplied them with incomplete information, the mistake is the universities fault. However, the universities only impose the rules for studentship funding, they do not make them and it is not their money. If your residency status does not qualify you for a grant there's nothing they can do about it. The only discretion they have got is to charge you 'home student' fees, which they have offered to do.

If you feel that your status does qualify you for research council funding and the university have made a mistake then write to the registrars office. Also contact the NPC (National Postgraduate Committee) who should be able to give you advice and support.

I am just confused. The PhD oppurtunities which are advertised as "non-EU/UK students eligible", Am I eligible to apply for them. BTW, I never visited UK and have been in Europe since last one year only.

If the project is advertised as "non-EU/UK students eligible" then you may well be eligible to apply. It does not necessarily mean that funding will be available to you.