TOPIC: advice Vs Advices

Which one of the following is correct?
1)I enclose two credit advices for your retention.
2)I enclose two credit advice for your retention.

Thanks

Actually, neither is correct because the word "advice" is uncountable, which means you can neither add -s to make it plural nor use a counter such as "two". Just exactly what are you providing the customer here--- letters, receipts, slips or what? Depending on your answer to this question, #2 could be corrected as follows:
2) I enclose two letters of credit advice for your retention (perhaps here you could use " for your files"). or
2)I enclose two letters of credit for your retention (perhaps here you could use "for your files") or
2) I enclose two credit advice notes/ letters / slips / receipt for you retention (perhaps here you could use " for your files").