Price increases

Why is it when I signed up for phone and internet I was given a set price. When I asked if it would double in a couple years, cause it usually does, the answer was no that this was the price for the internet and phone bundle and not promo. I was given a $10 discount when I signed up for auto pay. Shorty after it was dropped to $5 because I didn’t want to connect it to my checking account, ridiculous increase. Why would anyone give direct access to their bank accounts. And a couple years later now my bill is double what it was, I specifically asked about this. I don’t understand how they can justify doubling the price, even if it were a promo. Obviously the profit margin is huge. But it’s the misleading sales tactics that really gets me. I switched my phone to xfinity to save money, now I’m right were I was before but with worse telephone service. How does xfinity keep getting away with this? Why should I stay with xfinity at a higher price?  There are other services with a higher rating for a lower cost?