Hello Atsaeni,
I am not sure about the Solomon Islands but here in the US you cannot use the same credit card number on a second Paypal account. They say to remove it from the old account, which you said you did, and then you can use it on another account. Since you closed the account I don't think you can verify that it is completely removed. Maybe Paypal needs some time to update the records on their end.
If this issue still persists the next day then I would recommend you contact Paypal customer support and make sure that the card has been removed off the other account in their system.
