An Affidavit for a till slip

Terrible experience. Misplaced my laybye slip. Went to the the store told them and ask if I can take something and add on the money I placed my laybye on. They said no I need to go and make an affidavit state why I can't find my slip. How ridiculous is that. Does consumer act know that people are made to go to police station just for a slip. The service is really appalling even the workers there they seem confused by it. Even the other lady there not sure if she's a manager or assistant manager didn't seem to care said 'I can do whatever I want a lot of people have failed'.