Old Vehicles & Disrespectful Customer Service

I would urge anyone thinking of using Dan Dooley Car Rentals (DDCR) in Ireland to reconsider. As per several online reviews I found that their vehicles are old with high mileage on the clock. But their customer service usually gets good reviews right? Not in my case.
I live overseas and rent vehicles several times a year in Ireland when visiting on business and leisure time. I have rented several vehicles with several different companies and feel relatively well versed to speak about rental car companies. I won't go into massive detail on my issues but here is a synopsis from my most recent rental and my first time with DDCR:
1. The-car was three years old (2009 model - rented in 2012);
2. There were 124,000 kms on the clock;
3. The inside of the car was dirty and rattled due to age of vehicle;
4. The car had a flat tire.
After I complained, the CEO personally offered to assist in my next rental which is upcoming in June. Redemption for DDCR I thought! Not so. After much to-ing and fro-ing over emails their "best" offer was a 6.4% discount on the rate I could have booked that day online. Not really good enough. As a colleague of mine had already booked with DDCR three weeks previously I asked to be given his rate which was 6 euro cheaper per day than mine. Here is the response verbatim from Pat Dooley the CEO of Dooley Car Rentals:
"Sorry it is too cheap and that period is filling up fast. Maybe next time. Best Pat"
Sorry, but there will not be a next time. Nor will there be for the many dozens of people I am going to tell about your customer service or lack thereof.
UPDATE:
1. I can today rent the vehicle online for Euro 54 cheaper than the aforementioned "best" price I was being offered by the CEO of Dan Dooley Car Rentals.
2. Dan Dooley charged me for a full tank of petrol despite only using half of it. This was NOT explained to me upon my rental of the vehicle.
3. Dan Dooley has contacted me and this website to request that this review be taken down. I am refusing. The customer service and frankly abysmal lack of respect I am being shown by this company needs to be heard. I am entitled to my opinion.
4. I have offered to discuss this via telephone but Dan Dooley has chosen to e-mail this review centre website instead of speaking with me directly.