Hi Rebecca
Firstly your phone will not remain on as there is insufficient charge to keep it on ( the battery is not charged ).
Which leads us to the second issue, the phone not taking charge. It is quite possible that the contacts in the charging port are worn and not making contact with the charging port plug.
Solutions:
* Buy an external battery charger and charge the battery externally overnight ready for use next day.
* Or you may be able to get the charger and phone to work if you '''carefully''' move the charge port plug around inside the charging port in the phone. I say do this carefully so you will be able to see when the contact is made ( when the charging led comes on) . If this occurs ( the contact being made ) then you must find a way to support the charger plug and phone in this position to get the phone to charge.
Hope this helps
Regards
Prometheus 1618