I have a pair of boots—exactly what you are describing, from a brand called Miz Mooz. I bought them at a store in SF called Shoe Biz, a few years ago. They have a flat heel, come to mid calf, zip up the back, and have a scrunched black leather that looks great. I wear them with jeans or with skirts. They only cost me $119 and have lasted for 3 years so far (and I wear them all the time and walk a lot in them). I am not sure if Miz Mooz still makes one with a flat heel but you should google them and check it out…