Spurious discounts on bill

[#1]

My bill this month has some unknown discounts on it. Please could someone advise why?

Promotional discount + £4.20 04/05/20

Discount                     - £8.69 19/05/20

Discount                     - £8.99 19/05/20

They are in my favor but no idea what or why they've appeared.

Thanks   

[#2]

Hi @Buzzlockie, I've looked into those and sent an email out for you. If you've got any further questions feel free to PM me. Thanks!