Quick Reply: For a delayed government or corporate payment, the acceptance record is the document that decides the case — get that before escalating.
Direct answer. Small-business problems on this site cluster into setting up (registration and licences), getting paid (buyers, government departments, procurement portals), and compliance trouble (notices, suspensions, rejected filings). Getting paid is the largest group, and it usually turns on documents the buyer already holds.
The largest group here. Most cases turn on a record the other side holds.
If a department has the record you need and will not hand it over, an RTI application is the route that forces the question. Start with the RTI application format, and if the reply does not come or does not answer, the first appeal is the next step.