Lost Gear To A Bug

So after I just finished my ??? quest which I was excited about I saw a Nii Guardian and went for it but it pulled me into it in the river and I died which doesnt really matter but in the dying process I died 9 times, so I died 9 times in 1 death which sounds ridiculous but It happened and not only did I lose 9 LE which I didnt really care about but I lost my not even identified cosmic set... :(

Is there any way to get it back / write a ticket I also have a screenshot of it ?

 

Unfortunately, you cannot get the items back, but you should make a bug report about the multiple deaths.
Although it is possible you just had low soul points without realizing and lost a lot of items