Years ago I did credit investigations related to mortgages as a job. My info is perhaps a bit out of date but I'm not aware of any significant changes related to this. If you simply ignore an account that has a balance due accumulating on it, they'll likely charge it off to a debt collector as part of a routine batch process. The threshold where this happens varies but 90 to 120 days overdue is the common range. You could argue with the collection agency that the service provider voided the contract by their behavior, but honestly, arguing with a collection agency isn't gonna be easier than jumping through the hoops to cancel with these scummy service providers.

No. You cant do anything to someones credit unless you have their SSN. Damn good thing thats the case also, if you happen to be named Jane Doe or Bob Smith.

This is incorrect, see my other reply to you in the sibling thread.

Yup, the local city library dinged my credit report for late library fines ($18) and I had to clear it up to get a new mortgage. The library did not have my SSN.