complaint regarding service and unusable tablet

Put on R50 airtime on tablet but is shows R0.00 balance. Got account for R298 and were up to now unable to use tablet, therefore would like an explanation of how this is possible. The data shows it is blocked, how are we Suppose to get it unlocked? Who is local supplier who can rectify this or assist in showing how to work the tablet. I consider this \BRIDGE OF CONTRACT"as the service you offered are not rendered. i expect an answer ASAP or I will hand it over in the next 48 hours. The unactive tablet number is ***."""