ITC BA - NO SERVICE AT ALL

I received a call regarding an account settled the account the same day as it was a miscommunication from the company and then received no paid up letter or ITC Removal 3 months after..

I still receive sms's advising that I have to pay this account and when I call to query, they are not aware of the SMS sent out as they see the account is settled...

The last week I have been trying to call them and just no answer, I leave voice messages for a return call but no feedback to date

Can this please urgently get sorted out as I dont know where or who to speak to anymore