Ali Express — not received goods or a refund

Website:

Aliexpress.com

Two complaints whereby i have made orders, paid for them.
One black dress not received though the tracking says delivered. It has not been received to my address, the seller is not responding to requests for help, a new dress or a refund.
Second a green top which says seller cancelled transaction so the top has not been received, no refund or no explanation.
It’s impossible to complain direct to ali express so trying you for help.
Thanks