cheating by nearby.com

dear sir,
i had purchased itek in-ear bluetooth headset from nearby.com on 09/04/16 and paid by credit card and today when i went to chroma to take the delivery i was informed by them that there was no scheme by croma whereas the invoice clearly shows the name of chroma. today i called the tollfree helpline no i was told that in small writing below that we have to pay 499.00 extra. we requested them to pay back which they refuse and today last day so this is a fraud and such parties should be brought to justice.
thanks.