Exchange rate differences , help legal options

hI

WE ARE EXPORT COMPANY OF STEEL GOODS

DURING CURRENT YEAR WE HAVE RECEIVED REMITTANCES FOR INVOICE OF 2011 , 2012 , 2014 FROM 2 OVERSEAS BUYERS.

THE PROBLEM IS IT IS SHOWING TOO MUCH EXCHANGE RATE DIFFRENCES , RESULTING EXCESS PROFIT FOR US , MEANS INVOICE AT DOLLAR RATE OF RS.55 BUT RECEIVED VALUE OF RS.65 PER DOLLAR

PLS ADVISE LEGAL WAY OF JUST JUSTIFING THIS IN ACCOUNT