Connection troubles

I'm really fed up. My Internet connection has been dropping all day. The longest time it stayed alive was about 5 minutes and then it fell again. I gave a call to my provider but they were unable to resolve any problem at their site though they had already had few similar issues reported. I was playing around a bit to find out where the problem could be. I changed the Ethernet cable between my laptop and router, tried another uplink cable, did reset my wireless receiver. Still, it's been no use. The pings are bad and even if they are good browsing is still a nightmare when you have to keep refreshing the page in hope that it loads at last. Should I have a device for measuring cables connectivity it would certainly ease my effort to find out what's wrong. I suspect that the radio-router cable may be cut somewhere. I think I'll leave till tomorrow as it's fair late ... again.