Error code 3008 means the seller has blocked you for some reason. Since you seem to pay, and do not retract bids, the only reason I can think of that may be why you are blocked is that in their Buyer Requirements they may have set a limit on how many purchases a buyer can make in a specified amount of time. You might try asking them to check their requirements and if they find you have exceeded their limits to raise the limit or place your username on their exemption list.
The only other reason why you may have been blocked by them may be that you have not left any feedback for them or any other sellers in over a year. They may be saying they do not know why you are blocked, but do not want to give you the real reason for doing that. Maybe if you go back and start leaving them and other sellers feedback for purchases you've made in the last 60 days, they will remove the block.
"THERE IS NO SUCH THING AS FOOLPROOF, BECAUSE FOOLS ARE SO DARNED INGENIOUS!" (unknown)
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