Cancellation delay

I called customer care (808) on 31st March to confirm cancellation of my contract. I was told to call the next day as that is my last day of contract. I phoned on the 1st April and told to call the next day(I can only cancel the day after contract is finished) I then called on the 2nd April and was told the cancellation division is not taking calls and they will call in 24 hours. I called numerous times during this period and the call seems to go through for about 3 min then cuts off. I still have not been helped. I am still awaiting to cancel my contract. An email also sent to customer care sometime between 31st march and 1st April. I have had no response from them. My phone is starting to give me problems. I would like to take another contract(different service provider) but want to use my current number. I am being held back on doing so because of mtn. I am really frustrated and hoping to sort this out asap.