everything needs to come out of the cage. you need to wash the inside of the cage with warm soap and water and dry it completely before you put new bedding in the cage. i use shredded newspaper as it works very well. you need to be sure that everything in the cage gets cleaned. this is the only way your hamster is going to stay healthy.
are you doing something wrong. are you spending time daily making friends with your hamster. are you trying to interact with your pet when it is sleeping in the day time. are all of its food and water needs being met. did you start 