Jam,
I have (like most air-rifle users) my telescopic sights zeroed at 30 yards (roughly 100 feet or 30 of my paces).
This allows me to take closer shots by aiming under and if out hunting, longer shots if weather conditions allow (ie virtually (or better still) no wind) by aiming higher. My longest shot in perfect conditions was taken a day or two back, 48 paces and a good clean kill. If there had been a slightest breeze I would not have taken the shot.
BTW, my S200 seems to get on very well with AA Field Diablo 5.52mm (.22) pellets.
Let us know what the shop say's or does.
P