Customer Service is lacking!

So I rented a vehicle from them on the 12 of April, they did not give me a full tank of petrol, I brought it to the attention of head office! The people who were supposed to get back to me didn't. It's been 2 weeks and it still has not been resolved! I needed to use a vehicle again recently, the staff at the place were RUDE asking me various questions in an inappropriate manner!