Bill incorrect again...

[#1]

Hi. At the beginning of March I signed up to continue and extend my discounted fibre broadband and line rental contract. I think my March 2020 bill is incorrect as it has increased significantly from February.  
I have had incorrect Bill's everytime there's been any change to my account/service since I joined plusnet about 3 years ago.

I would also like to cancel bt sport but cannot find how to do this on my account. Could you please do this for me?

Chat isn't working and I cannot reach customer service in any shape or form at the moment.
Thanks.

[#2]

Ps there is no notice on the help and support pages that chat isn't working nor that there is a temporary change to telephone support opening times and reduced capacity due to the current crisis. This would prevent customers calling unnecessarily then waiting a few minutes before finding out.