Extremely unorganized ERP data

I started a new job as treasury manager for a company. I have used Excel extensively for 8 years but I have never seen such bad data organization. This company runs Hansa ERP system but the prior managers have copy + pasted data from ERP or manually input data into Excel with minimal formulas or data integrity.

What are your best tips to organize data? For example, if I download the trade payables, the data file will have a supplier number in B1, supplier name in C1 then address and bank info in A1 - A8. That is then followed by past dues in cells D9-15. And a total a few rows below in D17. Then a new customer detail starts after a couple of empty cells.

The data is 8-9k rows of data so manual clean up is not possible. Is there a way to clean such mess with simple functions or is this an ERP issue that should be addressed?