Slowest delivery ever

They are very slow with everything. I ordered from Shein some stuff it took them 3 days to bring it from JHB to CPT it shows 3-5 working days will my package be delivered but its been over a week now still waiting and can't get in contact with them and they don't reply to my emails it just keep showing 3-5 days since last week Monday. This is so frustrating specifically if you can't get in contact with them