Rain is a ****

I joined Rain wifi last year but , it started to give me a problem because of network. I canceled the contract in April 12 2025.I sent an email because you their phone is not accessible. I got a reply with a reference number. I disconnected their device and wait for them to collect as they promised. But I May 15 I was called to be informed that I have outstanding amount to pay.But I told the the contract was canceled the previous month. I send them the reference number for cancelation. They apologized and promised that I will get a call to arrange for the collection of the device. But still they never stop to call and send million massages reminding me to pay my outstanding that increases ever month.