i think i need help

Ok here's the problem there is a demon in my basement. I have always been sensitive to this kind of thing and I know its true. I have blocked it in one room but all my attempts to exorcise it have failed to the point where the demon is mocking me. I went down there to try again today and mark 3 was written on the wall. I looked it up and there is a verse there saying all shall be forgiving but those who mock god. What do I do.

Just a point I am using a room sealing spell that allows traffic one way to hell

You could use, what I call, a vacuum jar. Its used for negativity but could work here. After all, darker spirits feed off of negativity and whatever you call it (demon, evil spirits, phantom), If you take away the negativity than it will weaken the spirit and it will make it easier to cleanse. I'm not saying this jar will trap the entity, just the negativity it gives off. Take a glass jar and paint it black if you cant find one that isn't already that way. Make sure the lid fits really tight. In it place some cotton, a agate or quartz stone charged to absorb, some peppermint oil, some sage, and a lock of some sort (drawing a picture of a lock that is shut on a piece of paper would work to. iTs all about representation). Empower it, imagining all negativity is being absorbed into the jar and trapped. Place this either in the middle of the room if its the whole basement, or in the area that had the most negativity. Leave there for a full moon cycle than take it outside off your property and bury it. Try and do so somewhere that is still all natural, like the woods as eventually the earth will turn the negative energy into neutral. Than you can cleanse. Good luck.

thanks a lot