Tech Mahindra — query about offer letter

Address: 1-14A, janakayyapeta village, Nakkapalli mandal, visakhapatnam district, 531081rore

I from b. Sc background (2019passout) got selected for techm on june 26th 2019 which was held at bahdurpally hyderabad campus. I got an congratulating mail from techm on august 7th 2019 that i got selected and they provide an application form. Later i got an another mail on december 6th regarding offer letter with the role of ase and doj on december 16th 2019. But in nxt day i got an call that i got an wrong offer letter with wrong role, location, package and i will get an revised offer letter in few days time. It's becoming 2mnths but still there is no any information about offer letter. And they are not replying my mails. Please could you tell me how much time it will takes to get offer letter.