Why did you pay the debts personally and not the solicitors, what was the arrangement at the time?
Approximately how much money are they holding and is it the same as the debts which were owed or does it include proceeds as well?
There are strict rules about how long certain amounts of monies can be kept in certain accounts without breaching account rules (which are very strict and breach of which tend to be the reason for a lot of solicitors being struck off!).
There are also rules for accounting to clients for interest.
When you paid the debts off did you get any kind of confirmation of clearance you can provide to the solicitors?
Were the debts registered on the property or part of a consolidation mortgage where it was agreed certain sums would be cleared?
If the former then a discharge document should have been obtained in order to remove any entries relating to the debt in the title.
The solicitors will most likely have a duty to the new lender to have cleared the debts (and possible remove anything registered on the title) and register the new lender's charge over the property.
They may not want to risk breaching their obligations to the lender without proof of payment due to the possible consequences for them if the debts have not been cleared.
What kind of debts were they? Compant debts, private debts?
When getting your money back I'd ask for a proper breakdown in accordance with solicitor's accounts rules as to the interest accrued.