Normal Fibre 10-day fluctuations.

[#1]

After some back and forth with Sky, BT and Plusnet to resolve a long standing address issue, I was delighted to finally have had Fibre Extra Unlimited installed at my home last Friday. My property is literally just across the road from the brand new BT cabinets so was delighted that speeds were topping out towards the maximum transfer rates for this product.
That was Friday. Since then, the speed has been dropping and now appears (as of yesterday and this morning) to be stuck at around 18mpbs. Although this is more than I was receiving with my old ADSL account this appears to me to be more than a fluctuation. I completed the BT Speedtest which told me that I should raise a fault with my service provider and that there appeared to be an issue. I immediately jumped onto web chat with Plusnet and gave them this message but was assured that this was all due to the "10 day fluctuations" and that all should be okay after this time.
My question is, is this a normal result of the service initialisation? The drop from 70mpbs+ to hovering around 18mpbs seems a bit more than a mild fluctuation and is well outside of the expected service level I should be receiving. As I have waited a fair while to get the service rolled out, another few days isn't the end of the world but I don't want to be waiting around if this drop is more than a fluctuation, as I fear.
All speedtests were carried out using a single device connected via Ethernet.

[#2]

Hi, and welcome to the PN forum
There is no 10 day training period for FTTC connections so you would appear to have a fault.  There is, however, seemingly only a 10 day training period for new customer support staff hence the erroneous reply you got from Plusnet!  
I'd recommend going through the checks prompted by http://faults.plus.net and raise the issue that way - Best of luck.

[#3]

Well that has at least cleared up part of my question so thanks for the info.
The Broadband troubleshooter you have linked me to seems to indicate that I have been experiencing actual drops in my connection but to my knowledge this is not the case. The troubleshooter is asking me all sorts of questions concerning the dropped connection but I can't actually answer them as that is not the symptom I am experiencing. How frustrating!!!

[#4]

But assuming you finished the trouble shooter, Plusnet get the results as well for their faults team and then have to deal with it. Make sure you complete it then they can move on to the next stage 

[#5]

Troubleshooter completed with as close as truthful answers as possible. Let's see what happens. Thanks for the responses so far.

[#6]

I can already see the issue.
Give me 5 minutes.

[#7]

You can have as many minutes as you like if you can fix it too!
Thanks 

[#8]

Try a reboot?
Should be fine after that.

[#9]

Will try that ASAP and report back.

[#10]

One quick reboot later and we're back up to 70mbps+
Thanks to everyone for replying and Plusnet for sorting the issue so promptly. Pity the original support guy hadn't been so clued in, however all is now resolved.