Referral Discount Missing on Recent bill

[#1]

Hoping someone from Billing can assist. For the first time in years a referral discount is missing. 

I've checked and person/account that was referred many years ago is still with Plusnet.

I hope this can be swiftly resolved.

[#2]

Can any plusnet staff help???

Thanks in anticipation.

[#3]

No point in posting any issues here for plusnet staff to help with  Very disappointing.