Cannot get through to call centre to cancel line

I have been trying since 15 April 2015 to cancel my line but i never get through to a consultant. I am put on hold and the recording just says that due to high call volumes there may be a delay in answering my call. I have been on hold for over an hour every time and no joy. I need the line cancelled by 31 May 2015. I have sent emails and i do not get any response. <br> <br> ***<br> Number: ***<br> <br> Regards,<br> Candy<br>