Contract Period Expiry And Notice Period

i work for an IT company.
My contract for a one year period is expiring in a week. Last month I negotiated the payment for a contract period of one year post the current contract end date.
However i got a better in a week after this happened. I thought for 2 weeks and decided to take up the other offer. Now my company is asking me to serve notice for a month and to work beyond the end of contract period.
I have to return my ID card and locker keys and handover the desktop given by my company. How can I return these if they are not willing to relieve me by the end of current contract period that will end in a week?
I dont think this is legal. Can somebody please confirm?

Unless otherwise extended formally by written communication the contract will come to an end on the expiry of the period for which it was originally given. Also, a contract (fixed term contract employment, as it is generally referred to) is renewable by both the parties mutually agreeing on the terms and conditions set. Therefore, asking to extend the period for one more month is not maintainable by law. Since the employment comes to an end automatically there is no need of any formal handing over and if at all anything is required should be initiated by the employer only. Therefore, you can mail the concerned person that your contract will come to an end on such date and would like to carryout the handing over on that date and request him to do the needful so that there would be no confusion.
Madhu.T.K

I fully agree with Mr Madhu T.K. A fixed period contract comes to automatic end on the last working day of the contracted period. No notice is required to be given. However the employer generally harass the employees and not make FnF settlement including withholding of experience/service certificate. If your new company is agreeable to your joining without FnF and service certificate of previous company, then you can go ahead, or otherwise you have to talk with your HR Dept./Employer. to settle the issue.
With regards