Netstar account

I've been requesting for months that they send me a invoice showing the deduction ammout that reflects on my bank statements. To date when I download my invoice. There is about a R55 difference between their invoice and my bank statement. They tell me it's, because I have 2 devices in my vehicle. Which I understand. I do. But why can't there invoice reflect that. I need to claim the money back from the company I work for and with a incomplete invoice I can't do thet