I couldn't say, but in case of further problems you might want to follow some of the other threads complaining about poor speeds (such as this one), and look at the actions (like posting hub stats), and setting up a Thinkbroadband broadband quality monitor. If all is now well, possibly it was a local network fault that's been fixed, but if you're familiar with the diagnostic steps then you'll be better placed to get help if it recurs.
Also, the 150 first line support is all poorly automated and fairly unhelpful (as you've found) and if you do get through to the offshore first line tech support agents, they seem to be collectively and intentionally useless. Use 150 to check for any known area outages, beyond that the best route for help is these forums, as the forum staff are UK based and very helpful, and there's a good few customers who can help with diagnosing problems.
In extreme cases you can use 150 and navigate through to "thinking of leaving" which will connect you to the UK based retentions call centre who are usually very helpful, but you have to be clear that you're intending to leave if they can't fix a serious problem, it certainly isn't an everyday way of accessing telephone support for technical faults and outages.
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