New Contract Horror

I app**** for a cellphone contract last week and today I got a pre-approval sms saying that an amount of 369 will be debited from my account. I however want to change the cellphone I initially app**** for to something a bit lower and nobody is willing to help. I had app**** for a combo deal of 2 cellphones but I no longer need 2 cellphones I just need one and I would like to cancel the initial deal and start a new one before they start it but I have been on the phone with over 7 consultants who keep transferring me from one department to the next.

At this point I would like the initial contract I app**** for to be cancelled altogether because the service is absolutely shocking.