I can’t have my previous invoices sent through to me

am so disappointed at how your system works, I took up a phone contract vodacom some time last year and later in the year I took a data contract. My invoices were combined without my knowledge. I called in on January to get them separated. I need the previous invoices separated and I have been calling only to find that ‘the previous invoices’ can’t be separated. I am disappointed that I can’t get the previous invoices sent to me, i mean there’s even no manual process put in place for situations like this. To even think of it, I didn’t even choose an option for my invoices to be combined.