False information and Terrible service

On the 2nd November 2015 I took my bike, 2012 Kawasaki zx6r, to S4 Lifestyle in Boksburg for a valuation as I wished to sell. I was then met by Riaan Sadie. Mr Sadie then evaluated the bike and offered me R60k for the bike. I made him aware of a service that was to be done to which he rep**** he would do himself and buy the bike for R58 500. I agreed to the price and did the paperwork. On the 5th November I delivered the bike together with all required paperwork, keys, etc. I was then issued a copy of the signed purchase agreement together with witness and manager signature. Mohammed in accounts assures me that payment will be made in 4-10 working days. 7 days later I receive word that somehow the payment was cancelled. Going to the branch they tell me that of all the bikes submitted (6+ Bikes) mine is the only that was rejected for payment release with no reason. Riaan assures me that this has never happened before and will not give a reason for sudden cancellation. Riaan tells me the MD had one look at the application, which included my ID copy, and decided he does not want it. I am left with no choice but to believe some sort of prejudice toward myself for some or other reason.