SEVIIN GF SPINNING REEL

First, I must say I am not a professional fisherman. I fish quite a bit but don't regularly purchase high-end gear. I received a GFS2500 reel with a combo I purchased on St. Croix's customer appreciation day. I was not familiar with Seviin brand reels but thought if St. Croix is selling them with their rods they must be OK. The reel arrived and it seemed very nice. I spooled some line on it and observed that the drag was as they say "smooth as butter". I went out to use it the first time and had problems with the line getting twisted up around the shaft on the reel under the spool. This happened a couple of times. I observed that is was very difficult to get the "nut" off and on the face of the reel to be able to remove the spool and get to the twisted line. Things seemed to stabilize for a while until I went to use the reel this past week. Using the reel I experienced the worst tangle of line I can remember ever having. I ended up needing to take the spool off the reel to clean things up and ended up losing most of my line. I finally got things back together and continued fishing with the little bit of line I had left. A while later I went to cast and had the "nut" that holds the spool on the reel fly off, land in the lake, and sink to the bottom. I thought I could probably find a replacement "nut" for the reel, but then decided it wouldn't be worth it. Blame it on the standard monofilament line I was using? blame it on my inexperience? Maybe. I've had much better luck with cheaper reels in the past and don't think I'll be getting another Seviin.