CAN'T SEEM TO COMPLETE "PATROL IN BISMARCK SEA" OBJECTIVE

[SeaviewSkipper]

Hi everyone. I'm frustrated. My original patrol objective was to photograph a carrier task force outside Rabaul harbor. I did that and then decided to sink the two carriers I found, since they were at anchor. I sank them, snuck out of the area, and sent a status report back to base-Brisbane, Australia. I was given a new objective, which was to patrol in the Bismarck Sea. So, I went there, patrolled around and sank some ships. Objective wasn't completed. I continued to patrol around the objective "star" and sank more ships. The objective still wasn't completed. I was running out of fuel, so I went to Mine Bay for a refit, then headed back to the Bismarck Sea. I patrolled and sank more ships. I ran out of torpedoes and went back to Mine Bay for another refit. Then back to the Bismarck Sea. I sank more ships and used up all of my torpedoes again. I patrolled for a few days around the objective area. The mission objective STILL is uncompleted. I've now sunk 18 ships and 125,000 tons on this patrol, all but the two carriers and a destroyer in the Bismarck Sea.
I'm out of torpedoes again and don't know what to do. I don't know what the game wants from me. I would appreciate any help. Thanks. Jeff