Bad bad baad

I bought a phone in March 2018 and since June I have been having problems to charge it. I then took it to Hi sense repairs in Woodmead the guy that assisted me and took my phone in his office and after 5 minutes he came back and then the phone started charging. After a few days the it started doing the same thing. I then emailed Hi sense and advised them and they told me to take it back to the place I bought it from and they will contact a technician. This is bad service because I have to do everything. I need my phone sorted out or either replace the dam thing. You will not be able to contact me cause my phone is off( not able to charge)