Unhappy with data service

I AM disappointed with the Digicel Weekly Wantok Combo services offered.
The package for K14 includes 100 SMS, 100 minutes talk time, 100mb data and 100mb for Facebook.
The plans worked well except for the Facebook data.
Despite having a surplus data like 50 to 70 mb, I can’t access Facebook.
At the end of the week the Facebook data is forfeited.
Can I have a definite answer as to why this happens?
I paid for that and am not satisfied with the service at the end of the day.
My appeal to Digicel would be to make allowances for Facebook surplus data to be used regardless, instead of forfeiting.
Let’s improve on that and be more honest and transparent this time for mutual benefits

Dissatisfied faithful consumer
Golikuka Menihas