Pathetic service!!!!!!!

I never receive my monthly statements, even though I’ve asked repeatedly over the last few years. So when I pay my monthly instalment I am always having to guess what the exact amount is. When I then accidentally don’t pay the right amount, I get harassed about not paying and threatened with being turned over to accounts. So they DO have my contact details, they just can’t be bothered to send me my statement monthly, but then harass me about payment. Niw, 4 days after I did pay the outstanding amount, I still get harassed with messages saying I have to pay! I am fedup and livid with this ridiculously poor service!!!