Jet airtime **** on account holders

Jet is the most ****ming retail I've ever seen. 2016 they made me join their airtime contract without my knowledge and I did not receive that airtime I canceled it.. They did it again I was so surprised that I've been paying my account but my balance is still the same and I don't have credit so I decided to call the head office they told me that I have airtime contract of which I know nothing about and m not receiving any airtime