safe

we have a LIVE website, with active (recurring) paid subscribers...
every month - they get charged on their credit card through paypal.

(so far - all good)

now - while creating the next version, updates, etc -
on DEV - we migrated all live user info and started working with it
(ouch)
and then - all our paid subscribers - got a false message - that their credit card cannot be charged!

my question is -
moving forward, as we are going to have automatic notification on content added, newsletters, recurring payment, etc.

is there any safe method / workflow -