If the OP had held out a little longer he may have got two months free - If he had really held out; three - Experienced agents can give up to three months and don't really need to consult a 'superior' to do so. They will make a pretence of asking a superior, though more often than not they wil be chilling out for a few minutes with the customer on hold thinking the agent is asking a TL for permission...
They are told to play hardball to minimise the concession they are giving.
Unless he was a big user - if his usage was particulary high he would have been offered a mac code without argument and offered no concessions whatsoever.
+++++++++++++
Ex Plusnet Tech Support Agent
(Fired for not getting customers to hang up soon enough.)