Personeelskorting for KPN employee

Hi KPN mobile supports,

I am a KPN employee so normally have the discount 50% on KPN mobile subscription. Everything was correct until I renewed my subscription in November. Now the “Personeelskorting” in the invoices (Nov & Dec 2020) are not correct anymore, it’s the same for old subscription. 

I expect the Personeelskorting should update to the new subscription cost, so that I can get the 50% discount for the bill. Could you please help me updating that?

Thank you very much.