Battery Replacement service a complete Joke!!!

I took my phone to replace the battery. I was told that the phone would be given back to me after 24 hours. I was desperate and needed the phone for business so I was told that if I got it the same day (after 6 hours) I would void the warranty. I figured that that would be fine if I could just use the battery for another few months. The very next day, the phone went off even though the battery was at 34%. After another 2 days, my phone was completely dead! I don't know what sort of battery replacement these guys are doing but I would never do business with such. How do you use a new battery for 3 days???? I'm not impressed!