Debit Order of the line i dont have

This is my second complain- can this be fixed?? I dont have time for this incompetency or can my contract be terminated? This so unprofessional and waste of my time. I am being billed for a line that i dont have, i have raised this issue last month, I spoke with Dean who promised t fix the problem- i just received the statement and the invoice. i can see the credit note, but still- there is another number- *** that was debited. I dont have that number- I only received one handset- please can someone fix this!!!!!!!!!