Had Fibre for 3 months speed is erratic

[#1]

So another slow speed post. Yes i will have to do the BT speedtest on wired connection. But here goes anyway. Does everyone experience this. When i connected back in November i was told i would get around 70mb DL. I use speedtest.net to monitor my speeds on wifi.
Initial speed at switch on 69mb over the course of the next week speeds vary over the day from as low as 1mb up to 69mb but generally hover around 25 to 27mb over the last two weeks though its not got over 30mb. Upload and ping do not appear to vary much at all.
I am asking why i am paying for unlimited when it appears to be limited.

[#2]

I rarely get full speeds from wifi, wifi just isn't great for consistent speeds lots of things can interfere and cause speed loss. When on 40mbps with BT I would get between 20 and 30mbps from their hub 5 on wifi and on plusnet with the 80mbps service I'm getting similar speeds via wifi with the odd spike up to the mid 60's with constant 76mbps from a wired connection
remember the unlimited part is how much you can download/upload and not your speed

[#3]

Hi mozzyd,
Wifi speeds can vary hugely, it's very dependant on other wireless signals and any interference in the local area. It may be worthwhile trying different wireless channels to try and improve the speeds you're seeing: http://www.plus.net/support/broadband/wireless_broadband/

[#4]

thanks. was just wondering. i will probably invest in some homeplugs to shift it around the house . Alegeek sorry i meant the difference in pricing of the up to 38mb and up to 80mb ie if i'm only getting consistently 29mb why pay for the higher speed?