CHANGING OF CALL LIMITS WITHOUT NOTICE

I HAVE 2 CELLC CONTRACTS, I HAVE NEVER PAID AN ACCOUNT LATE, OR NOT IN FULL OR BEEN IN ARREARS, I USE THE PHONE FOR BUSINESS AND PERSONAL, MAINLY BUSINESS THOUGH. WHEN I TRUED TO MAKE A CALL THIS MORNING RECEIVED A VOICEMAIL STATING I HAVE NO AIRTIME. MY MIT ON MY CONTRACTS WERE FROM START OF CONTRACTS BEEN R16 000. AFTER CALLING CALL CENTRE, THEY INFORMED ME TEH CREDIT CONTROL DEPT CHANGED MY LIMIT TO R780 YESTERDAY, WITHOUT MY KNOWLEDGE AND WITHOUT INFORMING ME. I NOW HAVE NO AIRTIME OR DATA TO USE. I DID NOT GIVE ANY PERMISSION FOR ANY CHANGES ON MY CONTRACTS SO WHY DO THEY DO SO WITHOUT EVEN CONTACTING THE CLIENT. I HAVE A PHONE WHICH I CANNOT USE AND IT WILL TAKE THEM 1-2 DAYS TO CHANGE IT BACK TO AGAIN AS THEY HAVE TO APPLY AT THE CREDIT CONTROL DEPARTMENT. I HAD 2 CALLS THIS WEEK AS MY CONTRACTS ARE DUEDOR UPGRADE TO ENQUIRE ON WHAT NEW PACKAGES I WILL BE INTERESTED AND ADVISING OF NEW SPECIALS. THIS I FIND IS A WAY TO BULLY YOU TO GO INTO A STORE TO TRY AND FIX AND THEN THEY ACAN GET YOU TO DO TEH UPGRADES AT THE SAME TIME.I HAVE CONTRACT PHONE TA MOMENT WHICH IS USELESS TO ME AND AN EMBARRASSMENT WITH MY CLIENTS!!!! I DEMAND TO RECEIVE SERVICE FROM CELLC