Cognizant — pre joining formalities

I was interviewed on 24th november, 2018 in kolkata. I got a shortlisted mail on 28th november and later received a link to submit the assessment test but and I received the offer letter on 10th dec but didnot receivr any mail from [protected]@cognizant.com where I will be provided with the link to upload my documents and to accept the offer. While today I received a mail from c2c to submit the documents by 15th decrmber. Please look into this matter on priority basis.