ORDERD PARTS FROM KOENIC AND THEY REFUSE TO REFUND

WE ORDERD DROP SPRINGS FROM KOENIC WHEEL WAREHOUSE ON THE 1 SEP 2015. WE RECEIVED THE PARTS (DROPSPRINGS FOR A FORD FOCUS) AND WHEN WE FITTED IT ON THE CAR WE SAW THAT IT IS NOT THE APROPRIATED DROP MILLIMETERS AS WE ORDERD IT. SO WE CONTACT KOENIC SO THAT WE CAN SEND THE PART BACK, AND NOW THEY REFUSE TO REFUND US. BECAUSE THE SPRINGS WERE FITTED, BUT THE VECHILE DID LEAVE OUR PREMISSIS AND AS SOON AS WE SAW IT WAS WRONG WE REMOVED IT.. THEY SAID THAT WE DIDNT ORDER 40MM DROP SPRING, BUT WE DID....NOW THEY ARE SAYING THAT YOU DONT GET 40 MM DROP SPRINGS, BUT WHEN WE ORDER AND SPESIFICLY ASKED FOR 40 MM THEY DIDNT TELL US THAT YOU DONT GET 40MM.... THEY STILL SEND US THE DROPSPRINGS.... AND NOW THEY DONT WANT TO REFUND US..... PLEASE HELP