They may be a potential investor seeking an interest in accounts receivable of your creditor.
Creditors can sell all or partial interest in their billed but not-yet-received assets if they need instant cash.
Obviously, the risk to those purchasing such receivalbe assets is the risk of consumer payment, which they need to assess.
So they wish to assess the consumer before making such purchases. Congress has given such potential investors the right to review consumer credit reports, even though they do not have an actual interest in the account.
FCRA 604(a)(3)(E) provides a permissible purpose to a party who:
"intends to use the information, as a potential investor or servicer, or current insurer, in connection with a valuation of, or assessment of the credit or repayment risks associated with an existing credit obligation."
If that is their permissible purpose, then complaint of an FCRA violation may be unwarranted.
If with respect to a credit transaction not initiated by the consumer, they are expressly restricted under FCRA 604(c)(1) and (2) only to your name and address, and if properly reported as such to the CRA as a PRM inquiry, it should NOT be showing as a hard pull.
if showing as a hard pull, they apparently did not provide the proper permissible purpose as that of a promotional firm offer for credit.
They may even have obtained your entire credit report, which is an even more significant issue.