My phone doesn't charge at all, even when is charging while switched off. And I have tried it with many chargers and battery. But same thing keeps happening
Based on your description there is one very likely reason for your problem:
The USB port of your phone is defect. It is loose and has lost connection to the circuit board it is placed on, therefore no (or very little) power can flow through it. This usually happens by too many movements of the USB plug while inserted into the USB port (the USB plug works as a lever and the longer the plug is the more force it can put on the USB port of your phone - this is called "principle of the lever").
Depending on your phone and how large the hardware defect is, often it can be fixed by re-soldering the USB-port to the circuit board. However this require soldering experience and the right soldering equipment. In some devices the USB port is located on an small extra circuit board that can easily be replaced with a new board.
May be worth measuring your battery terminals with a DVM and seeing if its greater than 3.6V. If your phone is on charge but is in some form of a charge loop you can take out the battery and manually charge it up to >3.6V using a TP4056 circuit and some test probes (with steady hands, patience and a lot of care). I've only had a charge loop once before but i'm guessing its probably not what your experiencing.
If you want to see if your charger is active then you can plug in a USB charger doctor inline with your USB lead and that may tell you a lot.
Note - If your battery measures <3V, you may want to purchase a replacement (for safety reasons).