Turkish Airlines Didn't Pay the Compensation for Overbooking

I was not allowed to board the June 23rd Milan flight due to overbooking. They promised compensation of €400, stating that the process would be quick and that I could receive it either in Milan or Istanbul. At Milan airport, I couldn't get the payment as only the city center THY office handles it. Upon returning to Istanbul on July 4th, the relevant office at the airport informed me that they had no cash and that I needed to fill out an online form. They assured me that THY would contact me to get my IBAN details and transfer the money to my account. Despite 20 days passing and multiple feedback submissions and calls to customer service, my compensation has not been paid. They haven't contacted me at all. I've been struggling with this for days. They promise immediate payment and excellent care when you're denied boarding, but afterward, you have to deal with everything yourself. Please, just pay my compensation!