You need to contact the companies that you have policies/deposits with and tell them that you are no longer being represented by XXX and your new representative isXX and that they have permission to discuss your policies with them. Probably the easiest thing to do is to find a new adviser, and tell them what you have with who - as many details as you can and they will probably get you to sign a standard permission letter and they will do the work for you. You can ask the other company for your file, but you may find them unwilling to help, you could probably go to the data protection commisioner and they can as a minimum insist that they destroy your personal data.
Bear in mind that this company may still be getting trail comission on policies you have taken out and will continue to get this until you remove them as your advisers.