Can I take the mortgage interest deduction even if my ssn is not on the 1098 as the payer?

My husband and I were divorced in 2016. The separation agreement states that I can deduct 100% of the mortgage interest paid in 2016. The 1098 that was issued references both of our names but my ex-husband's ssn is listed as the payer's tin.  The mortgage company stated that he was named as "primary" and they cannot adjust this for a prior year's taxform.  They can only adjust this going forward.