Have they given you the keys back yet?
There will be a small daily rate of interest on the mortgage account, the estate agent will charge a cancellation fee. Presumably there is a home survey. The locksmith will be £200 or so. The solicitors will have fees. It's difficult to know without seeing papers but £1500 perhaps? Less the extra you sent them. The solicitor should not, however, be delaying in this as they haven't given you the keys and you should be entitled to take the house back given the arrears are settled, subject to the additional amount which they should be giving you immediately.
Yes I do and if he says that you can't get him until he has the final figure you have to tell him that is up to him and that any competent solicitor would have got that information immediately so as to get this resolved and you back into your house.
Be as diplomatic as you feel you need to be but you do want your keys back.
You're welcome. Don't forget to leave a positive rating so that I am credited for my time.