Thats a shame Emma, would harness chest pads help? Did you buy it from a shop? As I would be inclined to take it back if the harness doesn't fit as thats a safety issue?? Its so hard, you never know if they are any good til you 've road tested a few times. The duet lite back rest goes to three positions on the back seat, It is a comfy pushchair for the kids but just so heavy and hard to turn etc.