Overcharged and ignoring queries

I have used this company to rent with whenever I am in South Africa until one moment one of the partners refused me a rental due to a glitch on my credit records search,fair enough the lady who assisted me arranged another car through their patner but this car was wasy less amount than the original car,she promised that there were no cancellation charges and I was going to be refunded but u til today and there has been no response after various enquiries,this has been 2 months ago and still counting.for such a good comñany its such a shame that they could do this