Anderson Crenshaw & Assoc Maximum Security Threatened to ruin my credit by saying I broke a contract which I did not asking for $2032.80 Dallas, Texas

I had a contract with Monitoring Alert. When I moved I asked them to transfer it to my new address. I called them and they understood I would contact them when I was in my new home. They sent it to a collection agency which demanded 2,032.80 or they would ruin my credit. I called several times to Monitoring Alert and they said we had to call Anderson Crenshaw and Associations. We have tried to contact Anderson Crenshaw but could never get through to them so it appears that their number is not in service anymore. Though this has occured they still demand the sum of money for breaching a contract that was not broken at all.