Employer Letter for my work at Dell

Hi,

I am Pooja Mehta and I am an ex-employee at Dell. I worked with Dell from 2011-2014. I need a letter which includes my job title, duties and responsibilities. 

I need this letter for my I140 petition and I would really appreciate your help here. This is highly critical information for me.

Can you please provide me the correct contact?

Thanks,

Pooja