Poor and false Sales

We signed up for home security ,sales agent come to the house with forms we complete it he advice that we will be a monthly amount ,and i annual fee once off . He then said a tech will come and install next week and we will get remote as well .The tech come to the house when kids was home not sure what they did however the receiver was laying on the floor no remote nothing .We call the tech and complaint he informed me that my son was in the bedroom they just test radio nothing more ,i then asked him about the remote he said he will speak to him boss an revert ,nothing happened i called again he said sales consultant will call .He called on saturday apologise that the day he come everyone was busy so maybe we missed some information he then later ask for an email address to sent a quote for the remotes of R1000 i told why must we pay that when you come to sale your service you advise it included . I have emailed the customer service who takes forever to come back to you then come back saying 3 weeks later a sales rep will come out i have asked to cancel this service because it was sold under false pretends they now tell me to pay for the whole contact i found this to be a **** why offer someone a service and once they sign the terms change