Sony XPERIA M5

Hi, I upgraded to a Sony Xperia M5 in Janaury. After 2 weeks the phone started shutting down and the only way I can switch it back on is by plugging it into a charger. MTN said SONY acknowledged this problem and all stock was sent back. But since I don't have the original packaging, I have to pay to get my brand new phone fixed! This is ridiculous. This is your flaw THAT YOU ACKNOWLEDGED. <br> <br> I am already paying a monthly fee for a brand new phone, now you're telling me I have to pay an additional fee for a phone that will be in repair for 4 weeks, and from what I've heard replacing the battery won't fix the problem either. Please let me know what SONY's plan is to replace these phones already bought. I was a happy Samsung client and upgraded to Sony for the 1st time, so far not impressed at all...