Poor connections

At the end of every single month, from the 28th up until the 1st, our wifi buffers so bad. We are paying for a 10meg line but only running on 1.3meg currently. It is always the last 4 days of the month. I believe they are throttling us to save data, its a uncapped service. We only have one device running but the service provider tunes us the TV only is using all 10meg but we are not even using 2.