Legal Question in Real Estate Law in South Carolina

It would not seem likely that the mortgage would allow for any increase in the interest. However, without seeing the mortgage and knowing exactly what was raised and for what reason, its hard to advise. When you say "payment" amount, this payment amount could include not only principal and interest, but also different types of insurance, taxes, and possibly other things. Probably the best thing to do is to have an attorney review the mortgage. You can also try calling your lender and seeing what sort of explanation they have. Good luck.