Cancel Contract

Based on my previous experience I have to take drastic measure. My contract is coming to an end at the beginning of May. Last time when i had to cancel my other line my cancellation notice had mysteriously disappeared. so i am leaving a paper trail this time (as i was advised by the agent from Vodacom that I spoke to last time). i am therefore giving notice to cancel my contract when the current contract expires. My number must be converted to prepaid. Lets see if Vodacom can get it right this time around. i for one am not holding my breath