I was billed a pro rata fee for router i will recive in 10 days.

I paid a pro-rata fee on 19/01/20024 for a router im getting on 30/01/2024. I called their customer care/billing and they refered me to mondo who has refered me to MTN for clarification, and an MTN's billing agent told me that the pro-rata fee is valid because they activated the data on 19/01/2024.