Have I been overcharged for 3g?

I'm on a plan with Orange called Dolphin 15, it's a 24 month contract which expires this August and is £15 a month. Included is unlimited texts and 100 minutes. I recently was given an iPhone by a friend who had upgraded and put my sim in this phone, have only just noticed on bank statements that the last 4 months I have been charged £152.21, £104.18, £581.72 and £498.62 with internet and date usage driving these costs up. On the orange website it states that data out of a monthly plan is charged at rates of over 1000mb of data being £40, I have used 180mb of chargeable data for the bill coming to £498.62 of which it has charged me £461.729.Am I missing something? There should surely be no way that it is that high? I have not been abroad either.

Usually, most, if not all carriers will charge a fee by the megabyte or pay-as-you-go data. These kinds of contracts aren't designed for smartphones. My advice to save money is the keep the iPhone until your contract expires, but put the SIM in your old phone till then. Then, when your contract expires, you can bring the phone into Orange and sign up on a contract or a monthly basis, using the iPhone.

Hi i've been told orange charge a Wi-Fi connection charge to, this may be incorrect, but if not then every time you connect to your home network you get charged, i use vodaphone and my average bill is just £35