A Rule 43 order is immediately binding. Failure or refusal to comply can trigger civil contempt. This is not just theoretical: High Courts have found people in contempt of court for wilful default on Rule 43 maintenance. If you genuinely think the order is unreasonable or unaffordable or your circumstances change, resulting in an inability to pay or an inability to manage on the amount you receive, use 43(6) to vary the order, providing proof of your changed circumstances.

If you have not received maintenance payments due to you under Rule 43, you will need to provide:

A letter of demand (record the arrears; give a short deadline).
A warrant or attachment where appropriate; you can escalate the matter to contempt with an appropriate founding affidavit.

Remedies include a suspended sentence, periodic imprisonment or coercive orders designed to enforce compliance.