spelling correction Customer Data Cleanup

I have a single Excel workbook filled with customer and contact details that has become messy over time. Before I can use it for marketing and reporting, it needs a thorough cleanup—specifically removing every duplicate entry and filling-in or clearly flagging any missing information... (Budget: $15 - $25 USD, Jobs: Data Analysis, Data Entry, Data Management, Data Processing, Editing, Excel, Excel Macros, Excel VBA)