The reason why is on the "contact us" page. Unfortunately it's a common problem with the customer service centres for many companies these days.
We’re currently experiencing longer than normal wait times at our call centres.
Due to COVID-19, you may experience longer than normal wait times when calling in.
Have you tried any of the other options for contacting TELUS, including the online Chat?
Consider posting the details here about your technical problem. Perhaps the forum members can help you.