Unhappy about the service

I am not happy at all. I have been a Zando client for sometime now but they recently treated me like trash. Bought shoes (jelly sandals)online,got delivered at my house-correct size,put them on (in the house) they fit. Few days after I wear the same shoes to work and that's when I discovered that they are very uncomfortable. I could barely walk the whole day because of the discomfort (the plastic was almost eating at my skin). I survived the day and decided to contact Zando to return the shoes,I did indicate my reason for the return as "the item does not fit me well". They are refusing on the basis that the shoes were worn, how else was I supposed to know that the shoes are uncomfortable unless I wear them? Also the brand label of the shoe got rubbed out on that same day. Now they were telling me about returns policy etc. why should they sell me a sub-standard product and expect me to just take it? I did explain further that I have had a similar incident before (shoes being uncomfortable),worse that one even had a missing diamante that fell off on the very first day I wore the shoe but I returned those shoes and got refunded with no issues. So why am I being reminded about returns policy now when it did not apply in the first incident? So is this return policy designed for us to accept products that do not meet our standards? And then they tell me that they will return the shoes to me at MY cost. No thank you they can keep their shoes and my money and I will also make sure that I no longer buy anything from them or refer anyone for that matter.