I am utterly disgusted in the service I received

Altech informed me that I have an available upgrade on my phone contract by them. I then contacted one of their consultants to get more information on the upgrade. I was told that I would run out the last two months of my contract and then start paying for the new contract. After some consideration I did the upgrade but since then have received an email informing me that I now will have to pay two contracts until my previous contract has expired. Following this I checked online in MyAccount I realised that I have already been billed for a phone and contract which I have not yet received. After once again phoning their customer care I was informed that there is not only nothing that they can do about that, but that they have no idea when I would in fact ever receive my new iPhone 6 which has already been billed to my account!!!!! I pay a small fortune for my contract and this is the service I receive in return! Two months ago I got a account three times my normal amount because when dealing *141hash it told me I still had more than 1 Gig data left when in fact it had already expired according to them. What is a person meant to do?