Poor Online Service Delivery

I bought merchandise online using my account. I was given a delivery date, followed by a vetting process to establish if it really was me who used the account. Fast forward my delivery was delayed until a month later where the status of delivery on my profile changed to delivered yet I have not received my parcel. I started calling Truworths and at first they said they have a server problem with their courier and cannot locate my parcel but I should be patient. A week later same answer. It's been 6 weeks now and I am now being told someone received it on my behalf, when I query this I am being thrown from pillar to post and being promised that somebody will get back to me. The main worrying factor is that I have received my monthly statement and the item I purchased online is billed. How do I pay for something I have not received? How do I escalate this matter because everytime I call, I get the same response. This is my first online purchase with Truworths and I have been an online buyer from different retailers even overseas more than 5 years but this is the worst. I need help, I need my parcel or credit my account so I can just call it quits.