Hi just taken SIM only contract out 17 days ago and the signal is either non existent or at best 1 bar. Calls drop out and I am missing calls from people. I called customer service to inform them and they tried a few things but still no better. Call dropped out. Tried online chat. They raised a complaint. Received call back several days later and they gave me two options to try. Again no success. Can I cancel contract without charges?