The first thing to do is to dispute the charge. You can call them if you want, but the legal way to dispute a charge from your mortgage company is to send them a dispute letter in writing.
The written dispute should not be included with the monthly mortgage payment. You must mail it to the correct address for your mortgage company (it is usually the "correspondence" address on your monthly mortgage statement). I recommend that you send your dispute by certified mail, return receipt requested.
If you want to get technical, mortgage company disputes are governed by a federal law called the "Real Estate Settlement and Procedures Act" or RESPA. Under RESPA, your dispute letter is called a "qualified written request" or QWR.
The lender must acknowledge receipt of the QWR within 20 business days and must resolve the complaint within 60 business days by correcting the account or giving you a statement of the reasons for its refusal to correct it.
If you don't get a satisfactory answer from the lender, you may wish to consult an attorney. You may want to bring a lawsuit against your mortgage company. You may be entitled to statutory damages of $2000 plus your attorney fees. Meanwhile, you should continue to make your mortgage payment during this time.