Need help please ASAP

I am not selling I am TRYING TO BUY SOME TENNIS SHOES. But for two weeks now the Two DIFFERENT PEOPLE have not shipped them and I haven’t been issued a refund . One pair was for a gift that’s no longer a surprise. Now I ordered two more pairs and still aren’t getting much info on shipping dates … what’s the PROBLEM POSHMARK AND SELLERS. Send the items that people order and pay for !! Cause it requires a lot of work to get this money returned !!! Signed not a happy customers