Slow Internet Speed

For almost 2 years I was getting speeds of 280 to 320. My Gateway remained in the same position. 3 weeks ago it started slowing down. I was having trouble watching tv. My speeds were 7 to 30.

So far I have called 3 times in the last 2 weeks. On the 2nd call they sent a new Gateway.,  My speeds were still down around 20. Called again. Didn't get any better.

Last night my speed was down to 7 and I couldn't watch tv or do anything on the pc.

Looks like I'm going to have to switch carriers.

Does anyone have a solution or should I just go ahead and switch carriers?