Still billed on account that should be closed

I called twice in Dec 2015 to close my Kulula credit card with fnb and was given a reference number and told my account would be closed by 31 Dec and to call in Jan to confirm closure. I called twice in Jan and again last week. And was told the R40.43 would be reversed and my account closed. 2 days later i receive an sms saying my acct is overdue by R40.43 and must be paid to avoid a bad payment record. Please can this be resolved urgently and my account closed. This is now the secound month my account is open when it should be closed.