Notice period dispute (probation)

Hi Folks, I have resigned from my employer after completing 3 months and a week. My employer has asked me to serve full 3 months of notice period. However, as per my understanding the notice period should be only 14 days as is applicable during probation. Below is the probation clause in my offer letter. I have not received any confirmation regarding the confirmation of my probation. "You will be on probation for a period of 3 months from the date of joining. The period of probation is subject to extension at the discretion of the management of the Company, by another period of 3 months. Confirmation will not be construed to have taken place unless you are informed in writing by the Company to that effect. During the period of probation, your services may be terminated by the Company by giving notice of 14 days without assigning any reason thereof. Similarly, during the period of probation, you may terminate the contract by giving 14 days’ notice to the Company. However, the formalities of submitting proper letter of resignation and obtaining no-dues certificate from all concerned shall have to be complied with."