Worst experience ever

The worst experience ever. When renting a car with Europcar for Guyana, Georgetown everything was going smoothly, they were very helpful via email. But everything went side ways at pickucp. I paid extra to have a navigation system in the car, but when I asked about it at pick up the guy named Zuri who was at the airport to delivery it to me, said the car didn't have any. He calls someone and tells me they would switch cars the next morning, so the new one would finally have the navigation system. Next day came and I didn't hear a word for them. When I contacted them via email, they said they would delivery the device but would switch cars. Again, this never happened, so I asked them for a refund (of the price paid for the navigation system) at drop off.

At drop off, they said the car wasn't cleaned enough (even though I made sure it was clean) and charged me for the cleaning so the initial refund wouldn't happen