Still Apple is not letting cardholders pay off the balance or extra towards the monthly payment

I purchased a computer last month. Upon making the first payment I wanted to pay double but the system will not let me. Nor does it allow you to add the account to your online bill payment in your bank account. Absolutely ridiculous and predatory. This increases the chances that at some point a consumer can’t pay and they make more money. I’ve used lots of these types of payment plans from other credit cards and NEVER have I not been able to pay what I want or add it to my bank’s online bill payment account. Having to pay this one bill from a different location makes the chances of forgetting greater and NO I’m not doing autopay! I’ve had so many friends and associates tell me how autopay has seized double and triple payments when the current payment had already been taken and messed up their finances. Negatively affecting their credit. Why can’t we pay what we want over the balance?? Yet we can pay any amount under the balance which makes money for these financial predators? Isn’t it enough that we are paying the high amounts for the Apple products? Now, I feel as though Apple is a shady company and just want to pay the entire balance and close this card. Also, does it work the same when you purchase other items not on payment promotion? Will it also decide when and how I can pay off those balances? Afraid to find out! There may be more predatory surprises.