Audi (non-existent) Financial Services

I paid a lump sum payment into my account, to reduce my debt in August. On top of that I gave an instruction that my installment amount should not be changed and I also wanted proof that my capital reduction was actioned on time, before the interest rate hike happened. To this very day, I am still being ignored by Audi. Is it not the consumers right to make additional payments to reduce their debt?! I would not recommend financing your car through Audi, no matter how "convincing" or convenient they seem to be. Your balance will just keep increasing and no one will contact you when you make lump sum or any additional payments.