Harassment Phone Calls

This company calls me in relation to one of my accounts several times a day. I changed my Flexiloan terms with them some 5 months ago, reducing it from £3000 to £500. they took 5 months to inform me that my last £120.00 payment had NOT gone through.

My new payment is £20.00 per month, they now ring incessantly from various place around the world telling me and I quote that I am 6 payments behind.
This is only true in theory. Had they bothered to write to me I would have rectified the situation 5 months ago.

I do not appreciate being called at anytime up to 10pm sdometimes and no Sundays to harassing me for this last [OLD] payment.

How do I get off their autodialler lists, they told me when I last complained that they had done this but obviously they lied. I wish I had never ever given them my phone numbers.

I do not do banking type business over the phone and I do not intend to start either. Had they got their recrods straight I would have known about this and could have done something about it.

No letter was ever received and they have confirmed that no letter was ever sent out. In my view this is therefore their fault.