user credit payment

Hi

I would like to find out how i can use user credit to work the same as paypal payments. I want users to do eft payments to my bank account and then credit them in admin manually,the user should then be able to buy from any subscriber with his user credits but i want the payment to stay in admin as pending for period of 7 days to give buyer the opportunity to receive goods and then the payment gets released after buyer confirms goods received and if buyer does not respond in 7 days the payment gets released automatically to the seller minus commission owed to admin or if seller confirms that he has not received goods the funds can be refunded to buyer by admin and if someone wants to withdraw money from his account the system should send a verify withdrawal email to user so users can reply to verification email from his email address.

Kind regards
Morne