Ginny works for the Poptop Makeup Shop. She signs a contract with Glamour Co. for a shipment of lipsticks to be stocked at Poptop. Poptop never agreed for Ginny to be their agent, but are thrilled with the deal she struck, and decide to stock the lipstick in accordance with the contract. Poptop has a change of heart after closer examination of the stock. They wish to withdraw from the contract and argue the contract is not enforceable by Glamour Co. because at the time of signing, Ginny was not Poptop's agent.

Is the contract enforceable? If so, from what point in time?