Lidl slip esculation advice

Please can someone advise me on how to escalate an incident that occurred today at my local Lidl store. I completed an accident report and asked the manager to ensure the relevant CCTV footage from the store entrance is requested so the matter can be properly investigated. I am six months pregnant and am now experiencing pain in my hips and lower back following the fall on entry to the store where the floor was wet. The store manager was slow to address the wet floor and delayed placing a warning sign for other customers. His conduct was unprofessional, and he refused to provide me with any paperwork, stating that the incident report was incomplete and that he needed to check procedures as he is a new employee. I would appreciate guidance on the next steps to escalate this matter.