Turkish Airlines Ticket Cancellation and Refund Issue

I attempted to cancel my flight ticket purchased from Turkish Airlines by calling a number starting with 0850 that appeared when I searched for THY online. They informed me that out of the ₺6,669.98 ticket price, only ₺2,510 would be refunded and requested a deposit of ₺2,400 since we were two people. They assured us that this amount would be returned. We received a total refund of ₺4,910, but ₺2,400 of this was already withdrawn from our account. As a result, only ₺2,510 was refunded for our ₺6,669.98 ticket. We feel wronged regarding the refund process. The receipt for the deposit requested from us is attached. We request that the correct amount be refunded to us.