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I have a Schengen visa that has a 90 days validity and will be expiring by the 25th of February, 2015. I got an Internship and thought I could renew or extend my visa from here (Geneva) but was told that I have to go back to my country (Nigeria) for a new visa. The visa procedure takes a month and there is a conference that I would like to attend by March which means if I should go back end of this month, I may not make it to the conference due to the long application period. Is there any way possible for me to have the extension here until March?