I had a similar experience with Eurocars in the UK. I booked a Ford Fiesta for 20 days.
We arrived at the rental depot and waited in-queue. A young man seen us. I showed him my paperwork; okay there. He asked me how much traveling we were doing.
I said we were off to Cheshire near Liverpool for a week, up to Scotland, then to the East coast to visit friends, see York; returning through the Lake District to Cheshire.
He suggested a large car for the extensive distances; so I took a Volkswagen Golf. More fool me, more money to them. During travelling, I checked brake fluid and oil. To my suprise they were low; in a fairly new car with 10 days' driving.
They topped up the brake fluid but told me the oil was half full.
I checked the oil again - minimum again.
I ended up buying oil for it myself.
J Worthington, Tauranga.