Stalling tactics from netstar and trying to get money for no longer needed service

My three contract expired and they said I would be put on month to month contract. Payment on the 1st of the month means I am covered for the month. If netstar does not receive payment for that month then they would consider the contract cancelled. I tried calling netstar to cancel several times and as soon as the consultant is about to finalise the cancellation, suddenly the is a network problem and it sounds as if the consultant can not hear anything. Send to two emails requesting cancellation. After sometime a lady from netstar called and said she is processing my cancellation. On the 1st of the following month my account was not debited. Thank God the cancellation went through. They debited my account on the 3rd of month. I reversed the debit and blocked at the bank. They called saying that I have an outstanding amount with netstar. I explained the situation and the first few agents said they would escalate it. Now it is hassle to cancel the contract. I also explained the situation on the emails. It is clear that they choose to ignore the contents of the emails. They call, each time their consultant hangs up the phone. Payment for service and no payment no service. I no longer need their service.I would like to believe that this is a result of *********** staff . Calling on netstar management to sort this out.