As stated on the create node page which all users must agree to when creating any node: "I understand that failure to pay monthly fee within 30 days of due date will result in the smart contract automatically removing the node."
Once a node is removed for failure to pay, the node CANNOT be re-built, restarted, or otherwise re-enabled.
Any unclaimed rewards for that node are surrendered at that time due to failure to pay the monthly node fees. This is not reversible, you must pay monthly node fees to earn unclaimed rewards.
It is also impossible for StrongBlock to take the fees out of your wallet on a regular basis. All transactions MUST be initiated by the wallet holder.