Worst Kind of Dishonesty

We bought a motorbike from We Buy Cars in Silver Lakes Pretoria. Initially the service was excellent. However, we notice that the speedometer was not working, and the bike battled to start. According to the salesperson it was probably due to the fact that it was standing for a long time without being started and driven. We bought the bike in good faith that the speedometer was something small to fix, only to find out from the agents that the bike was in a bad accident, a total rebuilt and that none of the parts were even original and they refuse to work on it. With the report in hand we wanted to take it back, only to be told that we bought it like that, and even though we had a 7 day return guarantee, they refused to take it back stating that they will only buy it back for R10 000 less that the original price. (and we cant even get it roadworthy with all the faults) Worst kind of ********* business ever seen.