I am sorry to say that I had weight watcher scales and my husband ended up taking them out of the house before I threw them at a window. I don't know why they played up so much, we changed batteries etc. He went and got me a mechanical scales. (not digital) as he is rather methodical and believes them to be the most accurate and trustworthy. They were not cheap ones, I strongly suspect he bought commercial ones but didn't want to hurt my feelings so he never said. Funny man. They do wobble if I wobble but they get the job done.
I hope you can find some reliable scales, but I mainly just take notice at the doctors and use my home ones for a guide.
Have a fantabulous day.
Chelle