Poor car service delivery

I took my car for a service at Ford Fury Woodmead in the beginning of May, 4 May to be exact. The battery had to be replaced and i purchased a new battery. All went well until 2 weeks later and the car just died on me while I was driving, early evening, Saturday. It cut out completely and I could only get it to start again after a few minutes and luckily was able to get home safely. The next day, Sunday morning, the car was completely dead. I called in my insurance to assist and the guy said that nothing is wrong with the battery but that one of the connectors connecting the car and battery came loose. This is a nut that should never be or come loose unless made loose to change the battery. The insurance emergency assist guy just tightened the nut PROPERLY and the car had life again. I am disappointed in Ford Fury Woodmead as they endangered my life.