Proving how bad my broadband is

Hi,
Down in France, my broadband comes in by wifi from a community antenna about 5 miles a way.
I think the antenna is overloaded and the service provider is restricting usage but without saying so.
There is no alternative other than expensive satellite.
What is the best way to produce a log of the service I am getting in terms that the service provider will undersatnd?
Some form of log of the upload and download speed done every 5 mins or so?
Many thanks
Tony

Doing a test every 5 minutes would contribute to the problems if it is congestion.

Our tbbmeter software for the PC creates a best.csv file which is the best speed since over a short period of time each day i.e. monitors usage rather than creating extra traffic.

Another way is a ping monitor (http://www.thinkbroadband.com/ping) this runs on our server and pings you, ideally needs a static IP address so you don't vanish and latency can be a guide to when a part of the network is under heavy congestion.