Are you referring to form 1099-SA? This is a report on the distributions taken from your HSA.
Your employer does not send you this form; the HSA plan administrator does.
The HSA plan administrator is required to send you a copy of the form if any distributions were taken in 2016. This means, of course, that if you didn't take any distributions (i.e., used the debit card to pay for qualified medical expenses), then you would not receive a 1099-SA.
If you took distributions from the HSA, then contact your HSA plan administrator and ask for a copy. Your HSA plan administrator is the bank or financial institution that gave you the debit card to pay for medical expenses.
If you don't have the debit card, call your employer where the HR department will know who the HSA administrator is.