Installment to high / no birthday voucher

my installments are to high with stuttafords I have a 6 month interest free account . I currently owe only 1400 on my account yet my installment is 500 rand it's a joke I went into stuttafords to complain and they explained that is based on the highest amount I ve purchased on the account at one point <br> I refuse to accept this as I have accounts else where and do not have this structure with them . I will close my account with stuttafords it's ludicrous that they expect customers to adhere to this structure . I ve paid over and above the installment amount time and time again and the installment doesn't even lower when I ve paid in more . It's unacceptable to think I haven't even purchased on the account for 3 months now yet I have the exact same installment . Further more as an account holder I'm due a birthday voucher one would think stuttafords would forward this voucher before the customers birthday not after , my birthday is tomorrow and I ve not received my voucher . Stuttafords catch A wake up change it and I'll start spending again which is what you want correct ? Or leave it and I'll close the account your choice and I want my birthday voucher now stuttafords NOW