it depends on the services you require. most lawyers work on an hourly fee basis, but you can definitely request an itemized bill of the services performed. you could also negotiate a fixed fee or instruct them not to exceed a certain amount. in practice, 20 hours is not a lot of time spent on a project which could require research of the law, analysis and finished written summary. it just seems like a lot because you have to pay it! good luck. oh, and lawyers are not suppose to charge you for time in transit (unless agreed upon) such as thinking about your case while driving to the golf course or while playing a round of golf. get an itemized bill.
Presumably, you are working through Fidentia UK to carry out conveyancing on your behalf in Europe? Therefore, they should be speaking to their local solicitor and not you?
If you continue to have problems with them then you might want to speak with the FSA (Financial Services Authority) who are probably the regulator for Fidentia UK.