That site is OK it is owned by Ziff Davis however no doubt whatever speed it returned he would have tried to convince you that he could improve it.
Received one a few minutes ago from a man with an Indian accent apparantly called "Austin". Wouldn't give me a number to ring back, said it was a computer call! Wanted me to press the windows button + R. I immedaitely became suspicious and ended the call right there.
Two of the automated BT Tech Department your internet will be terminated today press 2 for engineer scam today so far.
I had a very similar encounter this morning with an Indian dude, telling me how he was calling from BT and he's here to give an upgrade to mine broadband. I doubted him straight away. He tried to get me to download "teamviewer" which would have given him control of my laptop. I hanged up, then he tried to call me back again... blocked that caller ID
After having about 20 scam calls from foreign speaking folk reckoning they were from BT I had one today from Talk Talk, obviously I hung up but it made a change 😉