Mail Merge Data Cleanup

I need help with a mail merge project using Microsoft Word. I have thousands of entries in a CSV file. Each person's information is spread across multiple lines and needs to be merged into one letter. For example. Mrs Jones has donated 5 times so appears 5 times in the list, but we only want to send her one letter showing the 5 donations.

The details to be merged include:
- Names and addresses
- Custom messages
- List of annual donations

Ideal skills and experience:
- Proficiency in Microsoft Word and handling mail merges
- Experience working with CSV files
- Attention to detail to ensure accurate data consolidation

Looking forward to your bids!