After many months I still did not receive my depost refund

I paid a deposit when I rented a car through insurance from First Car rental. This deposit is supposed to be returned. After many months and many emails I am completely ignored. I received no feedback whatsoever. They basically ignore me. I have no clue why they are not refunding my deposit. This is completely unacceptable. I send regular emails from the 6th of August, but First Car Rental is just ignoring me.