It is probably as a result that property taxes were not paid or there is a change in escrow. When I get these forms, it usually means there may be a change in the mortgage payment. Call your Chapter 13 attorney, he/she is the best equipped to tellyou what to do as they are familiar with the specifics of your specific case.
It is a claim by the bank that it is owed additional fees. Usually it can be paid outside the plan. You can object if the amount is exorbitant.
This answer does not create an attorney client relationship between you and I. I am not your attorney unless we both sign a written contract that describes our relationship and terms of the representation. Any information provided to you here is not a substitute for the advice you need to pursue any legal matter. I advise you to retain the services of a local attorney before taking any legal action in this matter.
Several mortgage companies have agreed to file documents with the bankruptcy court when changes are made to the payment amount of the loan. The reason for the changes could be a change in the cost of homeowners insurance, real estate taxes, late fees, or even a change due to an adjustment in the interest rate.
If you read the document carefully, it should say exactly what the charges are & what they are for. I have seen documents were the change is for as little as $6 because of a increase in property taxes.