Terrible Service

So I signed up for a sim only package in September 2019. Put my sim into my router and it worked until a few days ago. Then my internet was cut. After calling numerous times eventually they tell me my router is no longer compatible. SO I ASK WHAT NOW? Apparently they do not know. So I have a package which I can no longer access. I must have called them 10 times and still no answers. Just a suggestion, if you planning on changing your systems/packages why not contact customers first instead of cutting them off!