Do you manually unsubscribe a customers email if they ask for a refund?

I'm in the process of becoming a Clickbank vendor and need your opinion about deleting a customers email address from my list when they ask for a refund.

My plan was before I send each customer to the thank you page, I'd ask them to opt-in to a "paid-customers list" so I can offer other related products in future.

However, if that customer asks for refund with the 60 days, should I manually remove the buyers email from my aweber account or just leave it?

(I'm just concerned that they may be serial refunders)

 

I remove them unless they made multiple purchases and are only refunding one, or if they have good reasoning (like a double purchase )

In my opinion, it's better to not make a sale than get a refund or chargeback. So I manually remove them from aweber..

I also started with 2 lists. One for pre sales, one for customers. But after a while I realized I had many many doubles in the system. The same people that sign up for the pre-sales list are on the customer list. So eventually I did away with the customer-only list because of the aweber charges.