The Rev. Alvin Gwynn Sr. couldn’t believe it. His Baltimore church, Friendship Baptist, got a city water bill charging him $3,000 for using 700 gallons a day — mostly during weekdays when only one person was in the building.The reverend asked for a public works department hearing on the 2014 water bill; there, officials admitted error and promised to adjust the bill. But the next quarter, he got another four-figure bill — the original $3,000 plus another $2,000. Told he was limited to just one hearing a year, he asked for another in 2015, where the city again acknowledged error.But the mistaken bills kept coming. And the department stopped holding hearings, he said. With the agency having twice admitted mistakes, Gwynn’s church decided not to pay. In 2017, the city put a lien on the church, then sold the lien.Scrambling, Gwynn sent an employee to pay the bill. They managed to persuade the city to reimburse the lien holder.