Vodafone

Horrible Unacceptable and Ripping Off Services!! Never ever dare to think about signing a contract with Vodafone a gain!!!

I have been on a 12 month contract for £10.50/month for about 4 months now and have been over charged for every single months. Non of the bills are below £20 and the latest one cost me £71.60!!
Was told that I was charged about £50 for a number of calls that I made but were not answered, sometimes directed to voice mails. I asked them why did I have to pay for the calls that I didnt even get an answered? Also, they said most of these calls were made for just a few seconds like 2-3 seconds/ each and I got charged a whole full minute for each of them. How come they start timing the call when the other phone does not answer? and why charge the whole 1 minute while they are all just a couple of seconds long?
With all that questions, what I got was an unrespectful and unresponsive answer that this was all my fault, if I didnt go over my minutes I wouldnt have been charged that much, and Vodafone has nothing to do with this.
The network is also horrible, for many times I were not able to make or receive calls at all and was told that was because of my phone, not their faults @.@
Wanted to cancel the contract but they said I would have to pay full amount of the rest of the contract plus the cancelling service charge which goes up to over £100.
Being a Vodafone' customer is such a longest nightmare ever!!!!