Paid for third installment but still shows I need to pay

I purchased sneakers on the 16th of december 2024, paid my 1st installment and when it came to my second installment, I paid twice due to them sending me an sms about not being able to get money from my account. So I went ahead and paid on their system. Once i logged onto my banking app, I noticed that they had deducted already for the second payment, which meant the payment I made should have covered my third installment. When I keep checking the pay just now app, it still says I owe them for the 3rd installment which is not making sense when they have recieved two payments for my second installment. I have tried contacting them twice via email but have had no response since on the 31st of December 2024 Im just hoping someone can reach out and help me resolve this