Solar Charger not charging

Hi i bought a solar charger and installed it 4 days ago. It keeps saying not connected so i have uninstalled it and installed it 4-5 times but keeps saying the same. I read other comments on it , the battery is now at 73% and still dropping so it is not charging. I get cloudy weather here in Glasgow but i still thought it would have charged from daylight. Can you do an update to get it charging in normal daylight. I paid £50 for this and feel it is a waste of money. If you cant fix it i want my money back. Calum