Telus screwed up my internet?

Our optik tv wasn't working so we had to have someone from telus come and change the tv box but for some stupid reason they changed the internet box even though we told them the internet was working PERFECTLY FINE! Now ever since they've changed it some websites won't load, Youtube is all ****** up, and sometimes it's just super slow. I'm really annoyed and my parents don't know what card we use to pay for telus, so we don't know the pin number when contacting them. What should i do?