Debt collection — ERC (CA)

Debt is not mine. My mother in law inquired about a product for my wife and I at a previous address. We received a wireless box from XXXX XXXX XXXX which we never ordered. We called them and was instructed to not open it and just to return it back to the post office. We have been harassed by collection letters since 2013. We have responded and disputed all inquiries. We called XXXX XXXX XXXX Billing, Collections and Fraud department. They have no proof or documentation to support this debt as well as not being cooperative. The Fraud dept hung up on my wife. The billing said its valid but have nothing to support that we had an account with them. We ended up going with XXXX for our services for internet