PPI outcome confusion, any advice in this minefield will be great!

I recently had ‘The PPI Team’ contact me as they advised I could be owed some money. I accepted and followed on with the process, after a quick phone call I was advised to fill in some quick pre-filed forms and leave the rest to them. A month later after little contact from them, I was duly sent 4 successful financial reclaim invoices and was told to pay a high 39% service charge for each separate case. I hadn’t recieved any pre service costs, consumer information, what rights I had or an offer of acceptance prior to the claims - only the services rendered costs and what was left to me. I complained to them after advice from the Financial Ombudsman and they got back to me admitting complete fault giving a reduced to 20% (plus VAT) rate. Is this an acceptable outcome as my rights prior to the service were compromised by poor customer information including costs?? Or would you advise me taking this further? I haven’t got a clue where I stand and what my rights are.

Thanks