When an item is unlinked,it is marked as such in the db, everything associated with it is deleted, and it is removed via Plaid. The only reason to keep a record of the item itself is
to keep track of how many times it has been unliked to curb possible abuse. This happens automatically via a db trigger. Once the count reaches 3, it can no longer be relinked.

When an item is "relinked" Plaid generates a new id, which was being inserted in to the db and creating a "duplicate". The relink logic now includes updating the plaidItemId.

The was also an issue with transaction deletion when unlinking, fixed by deleting accounts and lettings the transactons cascade.