Do you have any unpaid item strikes on your account? They last for a full 12 months and with 2 or more you will find most sellers will block you from buying from them, for fear you will buy, and not pay.
If this is not the case, send the seller a message explaining you are blocked , and if they can place you on their exemption list. It will be up to them then to do this , if they wish.
@derek2007fish
