There are various reasons this could be happening:
Your account may have been temporarily disabled.
Buy/sell services may have been disabled.
Your account may not be recognized as a trusted payment source. Bitstack uses an automated system to help us protect the community and our site from fraud. There are two common reasons for this:
If we've received a chargeback when attempting to process one of your transactions, it may be preventing us from completing further orders. If you're aware of any chargebacks or reversals that have occurred on a recent trade, please include this information when contacting us.
In other cases, we may just need some additional information to confirm your ownership of the payment methods added to your account.