Resignation without notice after one week of service in office

Hi,

I joined a company one week back, and as per my employment contract, it is clearly stated that both parties can terminate this contract anytime without any notice.

However, I have resigned and the company is not accepting /replying to my email, and they're asking me to pay compensation or serve the notice period.

Is there something that the company can demand? Because in the contract, nothing is mentioned on the same.