Damage from invisible destroyer

I was executing a mission when i received damage from depth charges all the enemy destroyers were like at least 3000m from me and there were no planes tho i got a huge amount of damage and loss of crew as well as 6 zauns and 4 t1s ( since i wsant able to finish my mission i consider them a loss ) and lost mission ( not mentioning the pp and xp ) for which i prepared like 30 mins just for the possition :(. I didnt have red X or yellow sign tho people in chat were complaining about red Xes. I would like to receive my sub as it was unharmed, i lost trained crew as well 3 members tho level 3 and 4 ( 2 of each of the levels ) along with the torps. Thank you in advance tho do you have any idea with no sign of lag or delay or loss of connectiong why did this one happen ?! Since i was moving with 1 kn and i was able to look at all of the escort ships and i am sure they were so far away :( :(

posting it here on forum won't help. file a ticket at support: http://www.silenthunteronline.com/en...-and-support-0