Failure to service delivery

On the 27th of September I ordered a red jumpsuit on order number #10123 and till today I haven't received my order, I'm really disappointed at their service delivery more especially that each time Iam the one who keeps contact asking about when will they deliver. Today they sent me a what's app message replying on my message stating they apologize about the delay my order got lost. I find it so unprofessional and that they don't show customer value more especially this is not the first time I buy from them. I am greatly disappointed. I sent them a reply stating that I want a refund as my item I ordered they failed to deliver it but they didn't bother to reply to message. Is this how customers are treated?