|>>|| No. 23573
I don't know whether your phone would be affected by it, but apparently for a time "too flat to charge" was a real thing. Apparently on some phones the power required to kick off a charging cycle was more than the threshold at which it would shut off.
You might want to double-check that it is actually not accepting a charge by leaving the charger plugged in for an extended period (e.g. overnight), because it may be that while it's not displaying stuff on the screen it's still charging anyway. If that still fails, then it's probably an issue with the handset. If you have access to another phone that takes the same battery, try sticking your battery in there and see if it charges, or try and charge the battery from the other phone in your own.