GET BILLED FOR INSTALLATION THAT NEVER WAS INSTALLED

i HAVE BEEN A CUSTOMER OF MWEB FOR LAST ALMOST 20 YEARS,BEGINING OF JANUARY 2020 I APP**** FOR A FIBRE INSTALATION ,TILL TO DATE IT HAVE NOT BEEN INSTALLED.tHE LAST 2 MONTHS I RECEIVED A INVOICE FOR A FIBRE LINE AND INSTALLATION THAT NEVER HAPPENED.I CALLED THEM ,IST TIME I WAS TOLD THEY WILL LET THEIR MANAGER CIORRECT IT,BUT COULS NOT GAVE ME A CLEAR EXPLIANTION WHY THEY ARE BILLING ME FOR A LINE THAT WAS NEVER INSTALLED.A MONTH LATER AND GOT ANOTHER INVOICE SHOWING THE FIBRE LINE AND ALSO ARREARS ON MY ACCOUNT,AGAIN I ATTEMTED TO CALL THEM, WHILE THEY ANSWERED AND LOOK INTO PROBLEM THEY DROP THE LINE.I DO NOT HAVE A FIBRE LINE INSTAALLLED FROM MWEB AND THEY NEVER DID ANY INSTALLATION WHY DO THEY BILL ME FOR SOMETHING I DID NOT HAVE OR INSTALLATION THAT NEVER HAPPENED.?