Pinky, when you charge your phone to certain percentage and after that you plug out charger, does battery go down very fast?
Everything what i read, problem is in mini USB port. I had similar problem like you and when i change that part everything was normal. Changing that part will cost you 5€ max and servise will need 2-3 hours to switch it. I was stucked at 4% and you are at 50%. Mini USB port is problem then.
But before you go to servise, try to flash stock ROM. When i say stock i mean from huawei site. Where you need to put files in 'dload' folder. If that doesnt help, problem is in mini USB port. That is common problem for all android devices.