Very angry with Mytechzone

Mytechzone contacted me to take cellphone contract and then they said it will take 2 to 3 days to get my cellphone thn i agreed to take contract i waited 5 days thn i borrowed airtime from mtn thn i called them back that how cn they deduct 140 on my account after telling the agent that i asked her to call me back so yhat we can proceed with talking thn she sai won‘t able to call me back how but they called me to take contract now i took ths contract now Don't want to call i want my 140 plz