Contract law case example for an offer lapsing a specified time limit in the contract?

[oz]

Hi,

I'm working on some law coursework.

One thing that has me hindered is finding an example of a case where the contract was terminated as the customer did not respond to the offer within a specified time limit (i.e. someone promised to sell a customer 500 bails of hay, and asked them to respond within 1 month, but the customer only let them know after 1 and a half months that they'd accept, by which point the seller had already sold them to someone else) - this doesn't relate to the reasonable time rule, as the time limit is specified within the contract, but the only example of time lapses i can find online or in the text books refers to Ramsgate Victoria Hotel v Montefiore (1866), which is only applicable for the reasonable time rule.

Could anyone help me out with a relevant case to the sort of problem i made up above? Or failing that, point me towards the piece of legislation/act that specifies a contract will not be valid if it is not accepted within the specified time constraint?

Thanks