Ping spikes in gaming even with best possible speeds/package

[#1]

On ethernet, have best possible package but still getting ping spikes in gaming(league of legends)

going from 18-21 ping randomly to 100-120 etc. Also what at times feels like packet loss.

Likely cause is 4 family members using the internet, however many months ago i lived with my family and the ping was fine.

When i called Plusnet they said the line was fine and that the bandwidth usage from the family was likely the cause and the only solution could be to swap to a different company.. However in my area the only other decent companies seem like BT and Ghost which speeds and prices dont seem very different/good.

What thoughts do you guys have? 

Kind of unacceptable that im paying around 30 pounds for internet service that is complete trash. Should i change ISP?
I live in seaford(near brighton), so unfortunately not all ISP's are available.

[#2]

What result do you get for "BufferBloat" when you run the DSLReports Speed Test and clicking on the [DSL] tab ?

If you are getting a lower score than "A", then adjusting the QoS (Quality of Service) settings in your router should improve the BufferBloat result and you will probably find that the latency spikes disappear, and all the devices on your home network will feel more responsive.

Initially try setting whatever QoS bandwidth settings you have to about 85% of the pre-QoS speedtest results, and then incrementally change the QoS bandwidth up or down by 1Mbps at a time to get optimum results.

If your router doesn't have QoS capability, then buy a decent router that does, it is the only thing I've found that works to fix latency issues since Plusnet removed (what was previously excellent) traffic shaping back in June 2017.

If your line already scores "A" for BufferBloat, then your problem is more likely to be an issue specific to that game.

[#3]

I mentioned that im on a wired connection with an ethernet cable, 

does the QoS stuff still apply?

Unfortunately my router doesnt have QoS capability, what router would you recommend that does?

My ButterBloat results came back A overall, B on Butterbloat and A+ Quality,  i didnt run it with the game running at the same time, not sure if that makes a difference.