on fri. 12th july i accessed a website swingers and doggers.com   i
experimentally downloaded, and to my alarm the charges were mounting
at an alarming rate.  there appeared to be no exit provided, i had no
alternative but to shut down the computer, did this action break the
connection, and thereby stop the charges from accumulating at their
alarming rate.

Hello baluster-ga,
.
If your modem is powered by your computer i.e. if it is an internal
modem, by powering down your computer it powers down the modem too, so
would have cut the connection.
.
If you have an external modem that 'may' have remained live for a
while.
.
There normally is regulation of premium rate dialers. e.g. in the UK
there is a regulatory body
http://www.icstis.org.uk/icstis2002\default.asp
who:
"establish, maintain and ensure compliance with appropriate standards
of protection for users of premium rate information and entertainment
services and, in doing so, contribute towards the development of the
industry. In seeking to achieve this, ICSTIS will:
- Draw up and enforce an effective Code of Practice.
- Ensure that consumers are given adequate information to enable them
to take sensible decisions about the use of premium rate services.
- Operate in an independent, fair and transparent way.
- Reflect its accountability to the public and industry by operating
with measurable efficiency and effectiveness.
- Be adaptable and responsive to developments within a changing
industry environment."
.
Operating a premium rate dialer in the UK requires approval and a
audit if  you are acquiring use of a premium rate number from ICSTIS
and they have the power to fine and withdraw premium activities from
offending companies.
.
They also
"investigate complaints about any promotion or service involving the
use of a telephone connection (including Internet or interactive TV)
to make a premium rate call. Examples are:

- Services which start with the numbers 090 xxxx 
- International services commencing +00 xx and which involve Adult
entertainment
- SMS text messages charged at a premium 
- Information service (such as traffic and weather report services) on
mobile telephone short codes"
.
Although ICSTIS are UK based and your site may not be UK based or
using UK premium numbers, the fact they deal with +00 xx international
adult entertainment 'may' draw some interest from them to assist you
or forward complaint procedures.
.
How to complain http://www.icstis.org.uk/icstis2002/default.asp?node=33
.
You may find a local regulatory body of premium number usage in your
country or for the country the site is using for it's premium numbers.
.

I have been involved with the web design of a corporate dialer product
( http://www.chargitdial.com/chargitDIAL/DIALframe.html )
and a correct presentation of a dialer 
A. issues a security warning from an authenticated source e.g.
http://www.chargitdial.com/chargitDIAL/DIALemulation/DIALbodyemul05.html
B. issues a warning about charges
http://www.chargitdial.com/chargitDIAL/DIALemulation/DIALbodyemul06.html
C. issues a warning it will disconnect your normal ISP and reconnect
to the premium line
http://www.chargitdial.com/chargitDIAL/DIALemulation/DIALbodyemul09.html
.
The dialers are usually built by the supplying company for the
webmaster and will contain a disconnect button, time out after a
certain period e.g. 20 minutes or if they reach a certain price e.g.
$20 USD so there is no possibility for unwary users to be charged
hugely excessive amounts., even if they fall asleep at the monitor.
(Time out and maximum charge are defined by the regulatory body)
.
For you to have downloaded a unreputable dialer would either be the
result of a corrupt webmaster who doctored the dialer or a corrupt
dialer company.. or both!
.
To answer your question, no it is not right for the webmaster to not
allow you the disconnect option on a premium rate dialer.
.
I hope that helps,
regards lot-ga

Running an executable program from a sex-oriented site is definitely a
very risky exercise.

I doubt any researcher here will investigate this, but if they want
to, the website appears to be http://www.ukdogging.com/

You don't mention what country/state/province you are in, or what area
the dialer was dialing into, so what agency you might contact is
impossible to determine, but here in the United States, in at least
some states, it is possible to contest the bill and get a refund, as
the dialing was done (presumably) against your will. Basicly your
phone line was stolen.

However you did state that you downloaded the software & installed it,
which I am sure you won't do again, from an unknown site!