Best answer by Ryan
I'm sorry to hear this. Usually, when a payment is requested by CARS, it is best to pay through that method rather than through us directly just because they are managing the outstanding charge on our behalf.
We would need to access your account to see why you have received another letter, so if you could contact our Live Chat team here we'll be able to investigate this for you.
Alternatively, if you want help via email, you can contact us on CommunitySupport@idmobile.co.uk. Please include a copy of your post along with your username, your full name, your iD Mobile Number, your full address and date of birth to get us started.