Deductions & credits

Maybe "write off" was the wrong choice of wording.  I am just trying to figure out how to claim it because my tax guy is wanting a 1098 mortgage statement and I have told him that the bank does not provide such.  I have provided him with a statement showing the interest, but he states he can't use that.  Maybe he just has never done it before?  I am not sure - but what I am sure of is that I have not been able to claim the interest paid since I have owned the RV.  I am just trying to get some sort of direction on this because this is the second time I have discussed this with him.