Q: Imac connects to internet but wont load then drops connection

I bought my first mac a couple of months ago with an imac 21.5 i5. I love the os and im glad i made the swithc BUT, it was slightly slower than my very cheap laptop on the internet and slower than all other computers in my house and iphone at oading web pages, it often struggled to load a page, said unable to load ect but then would work fine for the past 2 days it has connected to the internet but will NOT load a page, or it starts to then stops, then wont reload, it drops wifi then picks it back up. all other computers such as the one im typing from work fine.

I am very dissapointed with the mac now and would seriously think twice about buying another, the store i bought i from was no help, i cant believe apple dont have support for products inder warranty. even working it is slower than my laptop that cost 20% of the price. I own a company tha relies heavily on the internet and this being my business computer has been a massive blow for me. I have changed nothing on the computer since getting it, no system preference changes or changed router ect and i have no clue what this could be. I could inderstand if it wasnt picking up with internet connection but it is, It is 5 feet from the router.

If i cant sort this it will be back to pc for me, i cant afford to have this happen to me again and ruin a couple of days of work. all in all I have lost a lot of faith in this brand.