I need an SMS system that works as follows (I accept suggestions):
1- The client sends a message "Example to 40000 (my gateway number)"
2- Automatically returns a sms to the client to be chosen: Enter 1 for XXX / Enter 2 for BBB / Enter 3 for CCC
Each option will deduct from the customer's cellular credit a different value.
That is my main idea, I accept suggestions.