Internet has been very laggy and slow

Everytime I do my business, trading in financial markets or sometimes play, i’ve been experiencing a slow and laggy connection, considering paying a large amount worth of $206, it gone up more after my router/ modem was updated and i thought it will fix the problem but it doesn’t. Your company doesn’t seem to live up with your claims which is “internet connection is reliable, high-speed, low latency, and robust network infrastructure to support various activities like streaming, gaming, and working from home”. It doesn’t feels like it. Here’s my problems:

1. Every time I open multiple tabs on either of my laptop or pc for my business the connections seems to slow down and keeps it from buffering too much.
2. I do trading and sometimes when I open the charts be it in my laptop, pc or phone it takes a while for the charts to load or I can’t see what’s in my chart, like the “candles” on my chart for example.
3. Sometimes when i hang out with my friends to play it’s the worst ever the game just keeps on lagging and lagging, always on a red ping.
4. When there are 3 or more people connected on the internet it feels like the internet just become slower than or around 50mbps.

Just want to point this out for you guys to fix it. I’m paying too much for a worst experience with your internet connection, $206 is an absurd amount of money to be wasted by a slow and crappy internet. 
You guys need to fix this as soon as possible before I pay that amount.