defective brand new ford ranger

took delivery of my brand new ford ranger 3.2tdci p/u d/c on 29/09/15. 02/10/15 just switched off in the middle of the road. contacted dealership and was told its a common problem and the pump needs to be replaced. they didn't have stock and vehicle was returned on 13/10/15. it broke down again on 20/10/15. got back from dealer 22/10/15. it broke down again 19/11/15 and went back to the dealer and was returned 24/11/15. after much enquiring I was told its common for the pump to lose water and that the engine seizes. furthermore my glove compartment looked second hand and the grill cover clips were broken. imagine my total disappointment when on Friday 12/02/16 the ranger refused to start. its back with dealership but they refuse to replace the defective vehicle. they now want to replace the engine. my brand new vehicle is barely 5 months old but its spent most of that time being repaired. I have contacted ford sa and after numerous emails to them and many consultants later, they said they cannot help. I should contact the dealer. im paying the bank a substantial amount of money for a vehicle I don't have and cant enjoy. please help me forward in this matter. shafee a karim