PMI Tax Deduction HELP

[Duane Hundley]

I purchased a house and closed in 2015 of July. I choose to pay my pmi up front in full at closing. It's listed on my hud statement and was $4,820. I filed my 2015 tax return and showed my tax preparer I prepaid the pmi. Well today I got a letter from the IRS saying they didn't show record of that and added the $4820 to my taxable income. So after research I know I'm able to claim this on my taxes but most places say it as to be broken down over an 84 month period. I think that applies to monthly pmi or does it matter? My next question is if it's suppose to be broken down over 84 months and the tax preparer didn't do there job correctly who should pay the $1200 taxes due plus the $74 interest charge? If the 84 months is correct I missed a deduction for my 2016 return and will need her to amend them also. Thanks