I am in the process of getting rid of private mortgage insurance (PMI). I was planning on paying off my loan down to 80% loan to value and then get rid of the PMI.

However, I was told by my lender that the 80% threshold only applies when I pay the mortgage "organically", month by month, until I reach 80%. If I pay a bulk amount to reduce my LTV, that threshold is 75% and that is by contract (that I signed). Is that correct according to the law?