Nissa Car Rental Cancellation Refund Stuck at Obilet

I rented a car through the Obilet mobile app from Nissa, then had the reservation canceled, but approximately one month has passed and the $85 I paid by credit card has still not been refunded to me.
Despite having reservation record number 17af7931 AA58, I have received no communication or follow-up from either Obilet or Nissa. I have tried repeatedly to reach customer service but have been unable to get through to anyone, and I cannot get a straight answer about my situation.
I am requesting that the $85 owed for this canceled reservation be refunded to my card as soon as possible, and that I receive written confirmation of the process and its resolution.