Fishing Reel help please?

im not sure about most of the questions but the knob for the drag gets looser the more u move it but needs a little elbow grease and take the cap off the reel and examine the line, check the lines not snagged on anything and cut off a few feet of it or maybe the reel needs oiling. zebcos arent the best around and even shakespeares(which are cheaper) are more dependable. if that doest work get your money back and get a new combo