Bosch Car Service dropping the ball BIG time

I took my car to Bosch Car Service Carnival Autobecause of oil mixed with water after overheating a second time (first time had no damage), had the head repaired, skimmed and gasket replaced (at least that's what I paid for). Got car back and the temp went slightly higher than normal the next day driving 65km x2 (return trip). Saw a slight oil/water mix and took car back and was told it is normal (not to worry about). 2 weeks after getting the car (and constant higher temps) I took it back again with more oil/water on dipstick and was told that I never complained about overheating when I brought the car in for the head gasket issue. My complaint about the car being hard to start when warm gets refered to the sparkplugs being old. As a favour they will replace the thermostat and water pump free of charge if I supply it myself. Another week in the shop and the car still use water and is hard to start (after replacing the spark plugs) - actually worse every time I leave it there. Sent e-mails to head office and no response 4 working days later.