Terrible experience

I moved houses and informed VOX on Jan 2 so they could cancel my service and start a new one. It took them until Jan 29 to get my line running. I still paid for Jan anyway because I know I'm supposed to give 30 days. I paid for Feb (the new line) but I've just had my line suspended for owing them. It turns out I was charged for Feb on the line I cancelled in Jan even though I got nothing from it. It's 12pm now, I've spent all morning trying to call them but ring ring ring no answe... I am so fed up with this company. I've had the worst experience with them.