Vodacom nightmare since changing from prepaid to contract

Changed sim from prepaid to contract. Since contract is active, my vodamail address stopped working. When you try to login, it tells you login details are incorrect. Changed password, got message from Vodacom confirming successful change, tried to login, get same login details incorrect message. Phoned Vodacom, they suggested I re-register. Did that, got confirmation message. Try to log in, same message again..... Vodacom cannot give answers.... It seems that their prepaid services just work way better and smoother than when you are on contract