MalhacanGateWay

I'm a new subscriber of DigitelOne ADSL plan 1.5 Mbps. However, for one month now I'm getting a very slow speed and this is the latest. However, when I'm running the broadband speed test add-on of Mozilla Firefox, I'm getting this one: 1.25Mbps. I don't understand the huge discrepancy and I'm not sure which one is accurate. I'll be waiting for your ideas on this. Thanks