RUNNING OUT OF SPACE (mobile mistake from title lol)

I don't know if I'm the only one having this issue but I got 6 retainers FULL of dungeon gear that I need to get rid. Easiest solution just bin it all and have plenty of space but I will appreciate if we could get crafting mats added on GC to exchange for seals.

I cannot start leveling other classes due to the fact I'm running out of space.