Your escrow account covers your property taxes and insurance. Double check, but your taxes likely went up. They didn't go up by $7200. When they paid your last taxes, the account was short b/c the taxes went up. So they paid the taxes in full, and you owe them that difference. They also re-calculate the payment so that you won't be short the next time taxes are due. So your payment goes up by the new amount needed, plus the past due from the last tax payment. Typically, you can contact your lender and pay back the past due in a lump sum so that your monthly payment won't go up by as much. But contact your lender to verify.

Tldr, your payment went up b/c your taxes went up. Your payment went up enough to cover the new tax amount, as well as your past due from the account being short for the last payment. You don't get a freebie on the shortfall from the last payment.