Hi, thanks for the reply.
I've had the phone since new and have never jailbroken it so this error must also relate to another fault too I guess.
I went on a car forum and got the answers I needed there. I had to re-download itunes, manually put my phone into dfu mode and make sure the user on my computer had admin rights to be able to restore my phone.
My phones now working great again although I've lost some data which is my own fault for not regulary backing up my phone in itunes.
I'm not having a go here but maybe Apple needs not to be so quick to judge. Like I said above, I've owned my phone from new and have never jailbroken it but was still having issues with the 3149 error code