Take the stage check and see what happens! Yes, 28 hours is a bit long but that could because the school sucks and is milking you for money. You lack confidence in yourself so you sub-conciously are doing things that are preventing you from soloing, etc. Way back when just before I was ready to solo I started making really crapping landings. Fear factor I guess. I took a week of and then soloed with no problem. The stage check went fine as well. One thing you should do is go round and round in the pattern if you landings aren't good. If you instructor isn't instructing and clearly offering suggestions to make improvements get another one! I see so many instructors that are in it for the hours and not for the instructing and that is a sad state of affairs.
Good luck,
AZPilot
Good luck,
AZPilot