Bad service

I bought a second hand 2010 Tata indica from the glen. Everything worked perfectly except for a leaking coolant bottle which i was promised will be replaced the following week. 2 weeks go by and parking lamps stop working and coolant bottle not replaced. i take the vehicle back and promised again the vehicle will be fixed. 3 days later vehicle has not been touched and i'm told parts are being ordered from india. A month goes by still nothing. 2 months nothing. Now its been 6 months and i fail to understand how it can take this long to replace a coolant bottle and fix my lights. every time i call i am told parts are there but when i send the vehicle i get a call back saying they are waiting for parts. the leaking coolant bottle is now causing problems with the starter as its leaking in the engine compartment. Today the car is chilling with them doing nothing after i was told the parts were there but low and behold parts still have not been ordered.This is absolute terrible service as the people who work there don't seem to know what they are doing. why sell a product you cant maintain or repair?