Battle to cancel expired contract

I have submitted my application form to cancel my expired contract and move my number to prepaid on 30 April 2015. Someone from your cancellations department called and stated that my number will be moved to prepaid on 31 May 2015. Today, on 1 June 2015, I am still on contract and all my included free minutes and data have renewed for another month.<br> <br> Please get your cancellations department to cancel my contract and move to prepaid immediately. <br> <br> Regards<br> Juan