Bad customer service- Cannot get a hold of anyone- just take deposits

We were really looking forward to having our pool cover installed after we were asked for a 50 % deposit, one expects you the supplier to also do your part. Every time we send a whatsapp message we get told we will advise 30 minutes before we come through.. that 30 minutes never comes. We never get a call back. We paid on the 17th of March. Teams have come out and had incorrect measurements, resulting in them having to return. Now we have a pool cover that is not installed as a team has not yet come back. After many attempts we just get the stupid generic message "We will advise 30 minutes before". Pathetic service. I don't think these teams are being managed so they do what they want knowing they have our deposits already