Fair enough

I arrived a bit early to pick up the car and was told I could only get another car by paying extra. When it was my scheduled time, the car still hadn't arrived, which basically meant they couldn't provide my car on time and tried to upsell me. The car finally arrived 20 minutes after my scheduled pick-up time. The return address was also incorrect, which caused me to wander around for a long time. Despite filling up the tank, they claimed it was slightly under and charged me 36 euros. A full tank costs just over 50 euros, and they wanted to charge 36 euros for a tiny discrepancy. It's outrageous.

Had to wait a long time while picking up the car and didn't know where to leave the keys when returning it at the airport the next morning, which caused a delay.

I was inexplicably overcharged and am currently coordinating through the rental company. Thieves are rampant in the Barcelona subway; I encountered two groups of thieves within five minutes, which was terrifying.

No full check up of vehicle before handover. Car was dirty and full of scratches and delivery person was rude to clean up. Finally with lots of arguments vehicle was changed which was good. Again no time given to inspect vehicle and person on duty was not interested to mark damage. Also he wrongly mark shelf in car which was not there. On returning person mark damage on Tire but same was not ask to check on handing over time. Since full coverage was there which safeguard for charges due to negligence of Hartz team. Great learning while renting car