Angry

My car car was booked for service in December 2017 , they said it's fully booked and they said I must call in Jan 2018 , I called and they gave me a date in 2nd week of Jan to go to woodmead. After service they refused to pay saying the car is overdue hence they are the ones that gave me that date. I paid R5500 whilst I am also payibg monthly instalments of R210 . What is the using of paying that money because my service can't be paid for. And again they are the ones that said they fully booked and gave me a date of Jan. I need my money back. My car Reg is FJ63ZN GP. ********** 841. I have been a loyal paying client. No debit order has bounced and this is the treatment am getting. This is uncalled for