Failing to successfully porting me off Vodacom

I have requested a settlement letter which I received and took to Cell C to port me on their contract buy-out to their network.<br> I then settled my device thereby ending my contract with immediate termination, yet my Vodacom sim is still active and I am now told that due to new systems Vodacom can only port me by 15 April.<br> This is nonsense and after numerous calls I have still had no joy - only excuses!!!<br> Can someone please contact me as I refuse to pay a bill for April when I have now settled the account and device cost in full on 26 March at Menlyn Customer Care.