BAD SERVICE AND BAD ATTITUDE

I BOUGHT A SELECTOR GEAR MODEL IN JULY 2017 FOR A MERCEDEZ BENZ AND THEY GAVE ME THE WRONG PART,I TOOK IT BACK WAITED A MONTH TO GET ANOTHER ONE AS THEY PROMISED TO LOOK FOR ONE. I GOT A REPLACEMENT BUT THE PART WAS FAULTY AND HAVE BEEN BEGGING THEM TO GET ME ANOTHER ONE OR A REFUND. EVENTUALLY I COMPLETED THE REFUNF FORM AND WAS PROMISED A REFUND IN 14 DAYS AND WHEN I CALLED THEM FOR A REFUND I WAS TOLD THAT THEIR BOSS IS NOT AROUND AND THEY ARE SEARCHING FOR MY REFUND FORM. I WAS TOLD IT WILL BE PAID ON THE 28TH OF DECEMBER ON THE DAY THEY ARE GIVING ME RUN AROUND WHEN I AM SUPPOSE TO GET A REFUND THEIR SERVICE IS PATHETIC AS THEY ALWAYS LIE WHEN YOU GO THERE