WhatsApp bulk messeges on iPhone

I own a vehicle Breakdown Recovery company and I would like to be able to send multiple messages to my drivers and my customers. At the moment WhatsApp only allows me to send five messages at a time which means it takes a very long time for me to reach my audience. I used to use WhatsApp broadcast feature but the problem with this is that, the recipients that don’t have your number saved never receive the intended message so there’s no guarantee that the message that you are sending will reach the whole audience that you are attempt to reach
As I am MOBILE and on the move a lot. I operate from an iPhone iOS not a laptop or a PC so I would need this feature to work on my iPhone please

Kind regards My