Scully Company

My husband and I have been tenants at Greene Manor Apartments in Mt. Airy for 2 1/2 years. In July 2015, Classic Management, Inc was bought out by Scully. We have always paid our rent on time and have had an excellent relationship with Classic Management.
Last night, December 21st, we received a threatening form letter on our door, for charges (which were not itemized) totaling over $363. On the letter (dated December 20), it stated if we did not pay the balance by December 23, they would take court action, for which we were responsible for court costs, attorney's fees and also the original balance. This left us 36 hours to pay the unexplained charges.
This morning, December 22, we say the property manager Tabitha (don't recall her last name) to resolve the issue. She printed out an itemized list of charges incurred since July for a reserved parking place ($50/per month - which we cancelled in June), water bills for Oct-Dec (which we didn't pay, our oversight, our responsibility) and interest charges. We resolved the issue with Tabitha by paying the overdue water, and were given a credit for the administration error on their end.
Our complaint is that we were issued NO NOTICE of anything, and then we had a 36 hour deadline. There was no written notice, e-mail or phone call. If we had known about these issues, we would have addressed them immediately, as we did today. But as such, all we received is a threatening letter with nearly no notice. Had we been away (it is Christmas week, after all), we would have had no recourse. Scully needs to have better communication with its tenants, with much more courtesy and lead time.