The stepper has gone flat. It does not elevate any longer. I have had it for one year. Is there any way to get it repaired?

I have severe fibromyalgia and other chronic pain, and I weight 90 pounds on a heavy day. This does appear to be a form of exercise that I could do, but I'd like to know whether I'm too light to be able to push the pedals down at the minimum tension, whether the not-adjustable cord tension is likely to be a problem for me, and whether this product is a good first "stepper" for someone who is not in great cardio condition to begin with. I DO have the discipline to use it regularly for short periods of time until I build up strength, but I'm concerned because very often I'm just too small or light for standard-sized equipment. An unrelated question: can it be used on a carpeted surface that has cement slab underneath it (a firm carpet) or must it be used on a tiled or wood floor?

I just bought the mini-stepper and the pedals don't seem to retract (i.e. come back up), when I step on it, the pedals just stay down, what do I do to fix this issue? thanks