Accidental one click prime activation during order process: is Amazon intentionally milking miss clicks?

I just accidentally activated prime whilst making an order. The app was loading a bit slowly so I clicked my smartphone screen and accidentally reactivated prime with one click. There was no safeguard. Now I have to submit a formal revocation in written form. I find this not only very annoying because now I have extra work because of a single unintentional screen tap, but also dubios. There should be a safeguard, it's standard design nowadays. Where can I file a complaint?