Credit limit for delivery & billing

Hi friends ,

In credit management we activated Oldest open items for 10 days .(Static credit check + Oldest open items 10 days)

Now , the client requirement is

Eg: X customer has 60 days payment terms & oldest open item 10 days .( 60+10=70 days )

i) After 60 days new sales order should be blocked .

ii) Only delivery & invoice should be accept up to 70 days .