This may seem obvious, but have you tried the link provided in that message?
That person/entity will likely tell you WHY they have declined to do business with you. I’d be willing to bet your credit card company has declined to allow this sale. It may be because they think it is a purchase that isn’t something you normally do. This is a good thing for both you and the credit card company.
At any rate, you won’t know WHY until you contact esellerate.
I have contacted the bank many times and they confirmed there’s nothing wrong with my credit card or the payment. I contacted esellerate but received no reply. The problem is that esellerate doesn’t accept the payment.