Well sir, I am by no means an authority on this type of thing, but I'll share what I do know with you.
Error 403 is some kind of communication between your browser and the actual website. This is most likely not anything to do with Telus. First step: check if the site you are downloading from requires a username and or password to log in, because some sites will restrict access unless you are logged in. Second step: I'm sure Telus must have a dedicated Tech Support phone number. These guys are usually faster to get ahold of than standard customer service, a **** of a lot smarter too lol! Best of luck to you!
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