Samsung S5

The phone went into samsung for screen replacing,when it came back it overheated,had to be recharged up to twice a day.It was then booked in at Tygervalley repair centre.I waited almost a month for my phone and when I received it back,the screen goes black.I am not prepared to book my phone in again and then be stranded without my phone again.I am paying for it after all,am I throwing money away because it feels that way