Cannot be charged for service I never received!

I have a new contract as of 1st May and have never once received the data nor made use of the sim card I got on the contract and this sim card though it is active and working. Today I noticed that I was billing 4 times the agreed upon monthly charge and when I call the contact centre no one can explain the costs and why I am being billed this after never receiving the data never mind not having made use of the sim card. Terrible service and I refuse to pay for a service I never got and as a matter of fact service is not what I had agreed on the initial contract.