If you were lending somebody €250,000, you'd probably want more back than you lent them. It's the cost of borrowing the money; you're basically renting money from them. Like if you rent a car, it's not enough to give the car back when you're done renting it; you also have to pay money for the cost of renting it.

Have you looked at your amortization schedule? Have you looked at the escrow papers that show how much of your payment is going into escrow to cover taxes and insurance? All the information is in the paperwork.