Broadband problems when it's wet!

[importanttobenice]

If it rains heavily, my broadband connectivity goes right down. Slow, disconnecting, etc. Sky Q not working.

I use a speed tester and it confirms the speed is right down. I envisage an underground connection that's getting wet. I've complained to BT and they say wet weather has no influence over connectivity. Unless I can get them to visit the property (almost impossible) when it's raining (very impossible), how can I get them to see this problem and try to fix it? Anyone else ever suffered from this?
Thanks 

[imjolly]

Are you a BT Retail broadband and phone customer

does your phone work when raining? Noisy?

[importanttobenice]

Hi

Yes I'm a retail customer with line, phone and Halo, etc

It usually breaks down after a long spell of rain - say all day or all night

I don't get any interference on calls if that's what you mean by noise?

Thanks