Home Insurance and Subsidence claim problem with AXA

Atomic_Suplex

Hello all. 

In 2014 I had some issues with cracks on my outside wall matching those inside, and various plaster cracking around the house. 

I called AXA my home insurers who assessed the situation. 

The upshot was that they thought there was a cracked and leaking drain at the back of the house. 

I had to pay for the cracked drain, but when the 'mild subsidence' (as the docs I have put it) settled, AXA came in, re-plastered and redecorated.

Some time later it all cracked again, but they just re plastered again. 
It happened again, and I took more photos, but AXA said it was nothing to worry about just an old house (without coming to look around) this time. 

When I renewed my claim I was asked if I should tick the box 'subsidence in the last 10 years' I was told 'no' because it was only the cause of a leaky drain. 

However I was only told this over the phone, (I think) by the guy who came round, so not on one of the recorded lines direct to AXA. I have no paper trail. 

I was never really happy that they had solved the issue, but it sort of seemed stable. 
lately I have seen more internal cracking that doesn't seem to move seasonally, it just gets a little bigger.
This week I noticed the pebble dash on the side of the house has started to from a crack from top to bottom. 

I didn't notice inside because it is at the back of a wardrobe, but when I inspected he paper and plaster behind the (fitted) wardrobe there was a nice big crack matching outside. 

So here is my problem. 

I checked my insurance and it states 'no subsidence in the last 10 years' TICK. 

I don't know if I ticked that box, but I guess I must have done after the advice I had from the guy who inspected the house. Then they have just rolled over for the last eight years.
. . . but when I look at the documents it they sent after the assessment of the work they did, it does mention 'subsidence' by name (minor subsidence )

Will this mean I have invalidated  my insurance and voided any claim I try to make on subsidence? 

Can I re-open the same case eight years on? I do believe it is the same problem and involved issues that they ignored the first time around? 
If it was considered a subsidence case wouldn't they have had to stick that on my policy themselves?  It's not like they don't have the claim I made attached to the policy. 

Help. I'm super stressed about this. I think the cracks I just discovered are a bit too big to ignore 
Thanks in advance for any help anyone can give.