New sim not working

I cancelled my 4G sim and ordered a 5G sim and router which I received. My sim is not reading in the router and keeps saying I must reinsert and restart which I've done several times. I called the call center and all I keep getting are reference numbers. I'm sitting at home with a router that isn't working being charged for it and getting no assistance. I need to be working now and this is frustrating me. It's been 2 days now still nothing, I even sent a DM on Twitter. Worst worst worst service ever, I just want to cancel this sim and get my refund