For now, if your service provider's DNS is messed up, try setting your DNS settings to the DNS servers found here:https://www.opendns.com/premium-dns/
It's completely free, no gimmicks...no ads or tricks, or viruses and what not. I'd of course contact your Internet Service Provider to see what's going on, and find out if they're having service issues... which I'm sure you know is going to be a lovely, long phone call, and probably one full of denials.... even if you could send them a Youtube video for evidence of your service not working or real time Skype/Facetime them and show them that your service was having issues.
But nonetheless, discussion with your service provider or searching their site, if they have a public posting of any news regarding service issues or like a public support forum would be the best start to find out if any others have had similar issues in your area.
Or as stated on the OpenDNS site, you can continue to use their DNS server information for as long as you like. However, if you continue to have issues with internet service, then it is beyond DNS lookups. As I've used OpenDNS for quite sometime, without issues as either my primary DNS or as a secondary and with multiple service providers and have no issues with DNS lookups.