Most reliable ISP?

So I've just moved to Reading for a year and I chose 4th utility off a comparison site as they had the best value - gigabit for £35 for 12 months. But the speeds have been atrocious (average 100, max 450) with frequent drops in connection throughout the day. Tried calling them, but I waited on hold for 2 hours without ever speaking to someone, so I'm looking to switch off ASAP.

From the cityfibre website, I've found that No One, Octaplus and Toob offer 12 month contracts in my area for sub 40 a month, which one would be the best to go for? Or is there another good, reliable ISP who offers 12 month contracts?

EDIT: Just signed a contract with Aquiss, lets see how it goes