Package ran out quickly and unusable top-up balance

Hello,

My 4G package ran out quicker than expected, I noticed the fast decrease since the launch of the 5G.
I decided to add an extra 1.25Gb to finish the month.
The package Flexi 1.25Go costs 4.750dt. I topped up the 4G Box balance to 5.705dt.
I am unable to buy the package because the balance is insufficient.
The message says : "Vous ne disposez pas d'assez de crédits pour acheter ce forfait"
Do you know that the amount of 5.705dt is greater than 4.750dt ?
If this transaction is impossible, please reimburse me the 5.705dt.
The 4G box number is 46296246
Many thanks.