Upgraded our plan in July and nothing but problems since!!

We were good 2 years then upgraded our plan in July when it was up to gigabit and nothing but problems since! Have spent way to much time chatting with friendly but unhelpful ppl at telus call centre.  They even sent us a new router exactly the same as the old one.  One of the tech even said oh well aren't all your devices 5g.  Nope didn't know it was a requirement (its not) but would be a lot easier.  Never would of upgraded but the lady doing it gave a good deal and said how much better it was.  How can we get this fixed.  It just cuts out randomly then takes 10 our 15 minutes to get it back.  Happened today, once yesterday then a few days ago!  Very frustrated with Telus!