Bad service and ignorance

I BOUGHT 3 ITEMS ON THE NET LAST YEAR DECEMBER, I WAS INFORMED THAT MY 1ST INSTALMENT WOULD BE MONTH END FEB 2015, ONLY TO FIND OUT THAT THEY DEDUCTED IN DECEMBER, THEY DELIVERED THE WRONG ITEMS AND I CALLED THE CALL CENTRE THE SAME DAY TO NOTIFY THEM AND I WAS TOLD THAT THEY WOULD COME COLLECT,UNTIL NOW IN FEB 2015 IM STILL WAITING, I HAVE BE HARASSED BY THE CALL CENTRE STAFF MORE THAT 3 TIMES ON A DAILY BASICS ASKING ME WHEN WILL I MAKE PAYMENT, I AM SO ANGRY AND IRRITATED BY THEIR SERVICE, BECAUSE EVERYTIME THEY CALL I REPEAT THE SAME STORY THAT THEY ARE CHARGING ME THE WRONG PREMIUM AND I DID NOT RECEIVE ALL THE GOODS, BUT STILL THEY ARE REQUESTING A PREMIUM OF WHICH THE ITEMS I GOT ARE NOT CORRECT. I DON'T WANT TO BE CALLED AGAIN UNTILL THIS MATTER HAS BEEN RESOLVED