When you approach Vodaphone regarding a contract.. Make sure you know what contracts you want. Check around with other networks for similar deals offering the same amount of minutes, data and texts. Then approach Vodaphone
and advise them that they are not the cheapest around. Ask if they can do any better with their price, then you may consider having a contract.
As soon as you start asking for PAC codes, they will always come up with a better deal rather than lose you as a customer.