upfront debit order no one told me about

I Have opened an account with Cartrack more than a month ago. I only got the time to arrange the installation due to no other transport. My tracker was only installed 04.07.2019. this morning 08.07.2019 got an sms and an email to say I failed to pay my account via debit order. The guy who phoned me to open this account never told me about instalment needs to be paid upfront otherwise I would have never let them install it on the 04th. when I asked him about what date is the debit order we need to discuss it his words was, someone will phone you after installation then only payment arrangements will be done. I am very unhappy cause the technician even said they will phone me any min now so I can get the app on my phone and my login details up until now no one phoned me. I am not paying an installment upfront otherwise they need to de-activate my tracker until 25th of June then form there on ill start paying. But I am not going to make payment arrangements for someone not doing their job right.