R4000 BILLING FOR OFFICES I NEVER USED

I RECEIVED A CALL FROM MBD ATTORNEYS SAYING THAT I OWE R4OOO, FOR OFFICE SPACE I HAVE NEVER USED. I HAVE NEVER USED REGUS OFFICE NOT EVEN SINGLE MINUTE OR DAY, NEVER EVEN RECEIVED CARD OR ACCESS CARD FROM REGUS. I ENTERED INTO A MONTH TO MONTH CONTRACT WITH THE CONSULANT I WAS DEALING WITH AT THAT TIME. CAN SOMEONE FROM REGUS HEADOFFICE GET BACK TO ME IN THIS REGARD!!!