URL Encoding to support special chars + and &

Question

I have a WCF REST service which retrieves data from the database. I would like to retrieve strings containing special chars like *, (, +, &, etc from the database using GET. I tried URLEncode of the query string. This works for some chars like *, (. But it does not work for chars like + and &. I would like to know of a way to retrieve strings containing + and & using GET.

Thanks