Not being able to make contact to actually find out about a parcel that still 2 weeks later has not been delivered

I have now for over 3 days been trying my very best to get hold of them. The call center just continues to say your call is important to us please wait" and even if you do your best to be persistent and hold on after 30 mins of holding on I have not once been able to speak to an actual human. I have gone onto their online "contact me" options, looked for email addresses and sent mails, low and behold still absolute silence to a client who has already paid for the service required. This is honestly becoming ridiculous