Worst rental experience of my life

Pickup was the worst rental experience of my life as I had made an online booking through an agency that I paid $1000 for in advance, but on arrival I was told the booking wasn't valid, so I had to make a new booking and pay again. I still haven't received a refund for the 1st booking so I effectively double paid for the rental. The staff member who assisted me seemed new as he had to ask for assistance from other staff a few times. The vehicle provided was nice enough, but not what I had originally booked. The vehicle was also dirty both inside and out and had lots of scratches and after having it for 1 day the oil check light came on and I had to spend 2 hours figuring out how to where to find the correct oil to fix it in a foreign country over a weekend which caused us to miss one of our planned holiday experiences. Overall the rental experience was the worst and most stressful one I've ever had and was a black mark on an otherwise good holiday, so I would find it very difficult to recommend to anyone.