About 10 years ago I bought a new mobile phone wioth a new SIM and when it came I thought I'd got a really good number as the number incliuded a double and a triple in it. However it turned out to be recyced and after a few weeks I got an unexpected phone call - turned out to be a landlord wonderign where his tenant (and I assume her rent) was, then over next weeks had occasional calls/texts from her friends followed by a full set of utility companies chasing unpaid bills. Next I started getting texts from payday load compainies offering loans then after about 6 months started to get the calls from debt collecting firms (who, to give them credit, were perfectly uinderstanding when I explained that the person they wanted had had the number in the past and they removed my number from their systems) .... this kept on going on a occasional basis for years - I still very occasionaly get a call like this.
Worst case was Scottish Power who started sending daily "your account is in arrears" texts to me - I phoned them to ask them to stop and got the "can In have the account number please" question - explained I didn;t have an account with them so I ddn't know them number so call centre person said there was nothing they could do I explained that in that case if I kept on getting texts I would be making a formal complaint of harrassment .... a couple of hours later got a call back to say that they'd "managed to search their database to find the account associated with my number deleted it from the contact details"
Also in the process of all these contacts I got to find out the full name of the person who'd had my number before,, the address where they'd been (one of the utility companies had helpfully asked me to confirm I didn;t live at that address), I could probably deduce the name of a gym where they'd been a member and also a hospital where they were being called for checkups