In the last few years I got a new number from Verizon after moving from one state to another, in the hope that it would combat robocalls. Not only did I experience what you did, but received a number previously used by a plumber who apparently had trouble paying his car loan. I was getting frantic calls at all hours from people with plumbing problems, and from Honda threatening to repossess a car. Verizon and other carriers even admit to recycling numbers as soon as 6 months after they were last used. https://community.verizon.com/t5/Windows-Phone/How-Do-I-Chec....
Your story reminds me of a similar one. I got my first cell phone around 2008 as a teenager. The previous owner also had problems paying her bills and that is probably why she ditched the number.
I got calls for literally a decade until they figured out she wasn't going to answer on this number anymore. At first, I would hang up when I heard the robo-voice asking for her, but the calls didn't slow down and eventually stop until I waited on the line for a collections agent to pick up so I could politely tell them to pound sand and stop calling me. Even then it took another few years.
Funnily enough, I recently moved out of the US and ported my number to Google Voice in case I want to come back in the next few years. My phone hardly rings with spam calls now.
Verizon and other carriers even admit to recycling numbers as soon as 6 months after they were last used
This has been standard for decades - it is a holdover from landlines. The companies only own a certain number of phone numbers. (Supposedly, when you change companies, 'ownership' of the number transfers to the new company). They've generally said that in more populous areas (or at least, areas with more phone numbers being actively used) that recycling numbers was the only way without changing the number format again.
I didn't think this was exactly a secret - but I could have learned this working for GTE/Verizon a couple of decades ago.
In the last few years I got a new number from Verizon after moving from one state to another, in the hope that it would combat robocalls. Not only did I experience what you did, but received a number previously used by a plumber who apparently had trouble paying his car loan. I was getting frantic calls at all hours from people with plumbing problems, and from Honda threatening to repossess a car. Verizon and other carriers even admit to recycling numbers as soon as 6 months after they were last used. https://community.verizon.com/t5/Windows-Phone/How-Do-I-Chec....