Their actions amount to a breach of contract.

他们的行为已属违反合同。

《牛津词典》

It's clearly a breach of contract.

这显然是违反了合同。

youdao

I have met every obligation thus far; so trust me it's not like me to break a promise (make a breach of contract).

我一直都在遵守合约；所以请相信我，我是不会不守信用的(不会失信的)。

youdao

MySpace could have brought a breach of contract claim against Drew for violating its user agreement (if it cared).

FORBES: The Computer Fraud and Abuse Act Is a Failed Experiment

Penney, which plans to sell the linens and cookware in free-standing boutiques within its stores, is not a breach of contract.

FORBES: Move up http://i.forbesimg.com t Move down

The union is preparing to take the DWP to the high court, arguing that the imposition of the pay scheme amounted to a breach of contract.

BBC: Official dispute sign