Secured loan sold to Arrow

Pathfinding

Having taken out a joint secured loan with First National back in 2005/6 it was sold on to Arrow. We were informed this had happened with a letter informing us Arrow were now looking after it, following the closure of First National. The original loan had included ppi. This was taken off the total after it was sold. There was no information passed to us about how new interest was applied, breakdown of the payment,  any fees etc. When the crash happened in 2008, my ex had to take a 20% pay cut to keep her job. We then got into difficulty repaying. In 2020 she had to give up work due to illness. I have still been paying towards the loan, but not the full amount. Recently we asked Arrow for a transaction history. Based on their figures, it would take almost 60 years to pay it off!

Have I any legal recourse here?

We did decide to sell the house and subject to contract, it has been sold, but with negative equity. Why is it okay for loans to be sold at a percentage of the amount, with no reference to the client? If the original company wrote off most of a loan due to closure of business, why are we expected to still pay the full amount to another company that has nothing to do with the original loan?

[Deleted User]

What happens to your loan after its been set up doesnt really matter too much.  They will have had the right to sell or transfer it in the T&C.   All you have to check is if the original terms that you agree to are still the same terms that are being applied now.   
If they aren't then you have something to look in to.   If they are the same ones you agreed to (however unattractive those terms were) then you cant really have a claim against anything. 

Tesco mortgages recently sold their mortgage book to Halifax.  Those Tesco mortgage clients dont get to just make the debt disappear.  Its still got to be repaid and as long as it is at the same terms as previously agreed.    
It happens all the time in this industry