Chris won't be back until Monday, but the tests he needs are as follows.
Head to http://testmy.net/ and create an account if you don't already have one there. While signed in to that account, and while using a single device connected directly to the modem with a LAN cable, NO ROUTER, perform five download tests using the 12MB manual test size. Make sure to space the tests at least five minutes apart. Also, because it sounds like he would like some upload tests as well, perform five upload tests, again spaced five minutes apart, but using the 2MB manual test size for the upload tests.
If possible, run the tests a few times a day, preferably morning, afternoon and evening. When you have completed some tests, click on "Results", then copy and paste the URL of the results page into a post on here. This will give a link on here to your test results. The link will look like the following, but with your account name where it says "yourname".
Also, if you would like to automate each batch of five download and upload tests instead of running each test manually, click on Auto Test and use the criteria in the following picture, then click "Start Automatic Test". This will run five of each test automatically. You will still have to do this a few times a day, but it will make it much easier than running the ten tests (five download and five upload) manually each time you run some tests.
(click on picture to make it larger)