Plusnet still taking DD after account closed

[#1]

I left Plusnet for Mobile but Direct Debit took money for next month for myself and my daughter.

I tried to contact Customer Service but, when ringing up to query how to get the money refunded, the contact number is permanently engaged ! How can I contact Plusnet ?

[#2]

Hi there, I've sent over a PM asking for some details. Please get back to me when you can. 

Adam

[#3]

Thanks for that. I have sent a request for a refund now for you What's the other number you need us to look into?