Worst delivery service I have ever had

I ordered a parcel over a month ago and still haven't received it, nearly 3 weeks ago it set for "out for delivery" I waited 3 days nothing I phoned and they kept saying it will be delivered today it never arrived, now after that 2 weeks later I am still trying, I have phoned no one wants to give me an answer about my parcel I've received 3 different answers, I have no idea where it is? The customer service is horrible some a so rude and don't help, the others don't know what the hell is going on and the one on WhatsApp was absolutely rude and useless they ignored my questions and now won't answer me at all. I have been waiting and waiting, everytime I ask it's was another 48/72 hours. Also twice they said failed delivery attempt but they never called sent me an sms or anything?? I was so irritated and I still haven't received it?! Lord knows when I'm going to