[Trical]

The rep said that they are not disputing if the item was there or not, they don't know and therefore I should contact my bank so a proper investigation can take place.

Nonsense.

How does an external source (a chargeback) help with their Internal Investigation protocol and procedures? Tell them to do their job they're paid to do - Investigate It and reply with the outcome.

I've just asked for it to be escalated and worded it quite strongly as well. Lets see what they say.