I signed an employment contract through a temp agy Feb 24 and have not received laptop to do the work. Can I renege on contract since no work has come

I signed an employment contract with a MD temp agency to do part-time copy editing work for an overseas company. The company said they were sending me a laptop in order to do the work, as the materials are confidential. The contract was effective Feb 24, the day I was supposed to receive the laptop. After multiple conversations, I was promised another laptop. This has yet to be delivered, and I am now unable to reach anyone at the temp agency. The contract is for 12 months; I want to know if I can cancel the contract before work has started. The temp agency never sent me a signed copy of the contract I realized.