ER24 AMBULANCE BILL IS RIDICULOUS

I had a fall back in September 2014 and was told over the telephone that it would costs about R 2,500.00 for the ambulance to take me to the Hospital. Two months down the line i received and invoice for R 7,344.00. There was no special medical equipment used and the distance traveled was around 5Kms. I disputed this with ER24 but never got feedback from them. Later, i was listed as a defaulter and now i have been handed over to debt collectors by them.