Is it permissible to benefit from a free minutes offer conditioned on the SIM card being inside the device and purchasing a monthly card of a certain value, and is it permissible to sell the SIM card for more than its usual price because it contains free minutes, and is concealing the conditions for benefiting from the minutes considered cheating?

There is no harm in buying a mobile phone that comes with a free credit balance if its price is the same as similar models and the credit is purely a gift. However, if the phone's price is higher because of it, then it is no longer a gift but a commodity. It is not permissible to make the benefit of its credit conditional, nor is it permissible to sell the SIM card at an increased price tied to the free minutes, because it is conditional upon something that leads to uncertainty (jahalah).