Are cable wifi company like videotron are aloud legaly to raise price monthly with out noticing a customer?

If it (increase in prices) is written in the contract, then you have been "notified", legally. It is your responsibility to read and understand the contract and the pricing. We all know no one really bothers to read all the details, but that is what a written contract is for. The contract is "due notice" of anything in that contract. If the contract was only for 2 years at a fixed, lower price, they can charge whatever they want after. However, you can cancel the service at point as well, with no penalty costs...

Unless you rent a router from the cable company, you don t pay monthly for WiFi. WiFi does not come from the cable company but originates in the router. Most ISP contracts have an initial contract period on a fixed price. During the initial contract period (often between one and two years) you have to pay a cancellation fee to terminate the contract early. After the initial period, the ISP will charge a monthly price that can vary month on month.

I hope this helps.