Vionic Women's Spark Desiree Ballet Flat - Comfortable Ladies Flats with Concealed Orthotic Arch Support for Plantar Fasciitis | Perfect for Work, Travel & Everyday Wear

I really wanted to like these shoes. I first purchased my size and the first few days they were comfortable. I did not experience any trouble breaking them in. They have good support unlike other ballet flats that hurt my feet after a day's wear, these have great arch support. Also, they are super cute in a nice navy blue with the nice stitching detailing.However, I did notice that after using them for over a month on a regular basis with my casual attire, they because super loose. I could no longer use them. No problem, I thought. I will donate these gently used shoes that became oversized to the Goodwill and I will purchase a new pair a size smaller. Well now into several weeks with my second pair in a size smaller, I am experiencing the same problem where they are getting too loose. When I walk wearing the shoes, they tend to come off my heel. I am not sure if I want to donate the second pair as well and just give up completely on this brand. In any case, I cannot use them when I leave my home as it's embarrassing to walk around in shoes that come off the heel.