First of all there is no criminal liability in case you are not able to complete a agreement or contract and there was not fraud,cheating on your part.
In case of civil liability they can recover the amount as agreed in case if the contract terms are not fulfilled. So as you agreed you can give them termination notice and refund the amount as agreed upon on termination of contract.
For further contesting the case and defences you contract papers need to be persuaded.also don't worry foreign company won't sue for 100$ as the litigation cost will be more than that.