Refused Refund

I bought a vehicle on the 27th Feb 2018 from this used It was a running Drive test done with the salesman Grant and offee to purchse On arrival to the vehicle now It does not start and the salesman diagnosed a dead battery. I bought the battery bt the car cud not start After several attempts attempts to fix it Asked for a refund as I cud not even move the vehicle out of the but the Manager refuses and made it clear they won't refund although they never alerted me of the deffects in the vehicle beforw signing the Please assist its almost a year now fighting