As stated on the sign up page which all users must agree to:
"I understand that failure to pay the monthly fee within 30 days after the due date will result in the forfeit of remaining and unclaimed rewards. NaaS Subscriptions that have reached maximum rewards expire on the day payment is due."
Once a NaaS subscription is removed for failure to pay, the node CANNOT be re-built, restarted, or otherwise re-enabled.
Any unclaimed rewards for that NaaS subscription are surrendered at that time due to failure to pay the fees. This is not reversible, you must pay 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.