First impression count, ADT not to be trusted

Good day to everyone. I write this because I can't get help, I accepted the debit check from this guy's, so that they can come and install the tracking device to my vehicle, they told me that they will come on the 10th last week Friday June 2022, till today still waiting, no call , no update, how can I trust their service in this regard. I called them no answer, I wrote the email no reply, what I need is to cancel with immediate effect, they have failed me, and I urge to the public that please do not do the mistake I have done.

Hope my matter will be resolved in no time.