I have paid my monthly fee every month as per their ads etc, YET my phone from them has been completely blocked and inaccessible to me on NUMEROUS occasions

I have paid my monthly fee every month as per their ads etc, YET my phone from them has been completely blocked and inaccessible to me on NUMEROUS occasions. They never communicated to me that my contract had come to an end and my buyout payment was due, they just debited a normal monthly fee. When I queried it they offered to let me then pay the buyout over 3 months. That's what I've done now, April being the last month. Payment made. PHONE BLOCKED SINCE FRIDAY 25TH APRIL 2025. All weekend I was back and forth with emails from my partners phone (because my phone is blocked) saying the same thing everytime(Names of who responds keep changing) - I keep trying what their instructions tell me to do, with the dame result. Still blocked. I sent them pictures from someone else's phone, of the screen I get on my blocked phone, even video now. Still blocked.