Unable to get Grim's Ghoulish Guitar

My game also says I do not own it, even after confirmation email of signing up but I believe (for ps4 anyway) this item came in the game already able to buy since I own all of the game packs it was there before the notification so I signed up for nothing. This could be because of a cross playform coding error and unlike PC where your game is updated through a computer, they don't have a way to check sony accounts through the PlayStation as a game support agent (escalated 3 times to 3 different clueless people) told me. Complete waste of time to talk to them if you play on console. But anyway here it is sitting in my game even though my home page tells me I do not own it. What a load of * that you have to sign up because it had been in the game files all along...