According to Vastu Shashtra the basement place is not suitable for business purpose. You should transfer your business place at other place having ground floor facing East, West and North. If it is not possible than you should follow the some following Vastu tips.
1. You should fix a Photo/Murthi of Ganesh Laxmi is North East corner.
2. Electrics items/Switch board should be at South East corner.
3. Your seating chair, Cash box should be at South West corner and facing East or North.
4. A Kubera Yantra / Kanakadhara Yantra should be keep in Cash box.
5. You should have good behave to customer.