Russtel S.A. LTD

Dear partners,
please be aware of Russtel S.A. LTD, as at the beginning of the last year they had a debt with our company Cualitel Telecomunicaciones, S.A. of around $42k.
It took some months in order to they make payments to us and at this date January 20, 2013 the debt is for $3,678.42. We proposed them that they offer us some routes in order to clear the balance. However the routes never were opened from their side.
They refuse to pay that amount as they said that there were some differences on our Statement of Account. However after conciliate we found our information was correct and since that day they don't answer our calls or emails.