Phone calls when contract due renewal

[Jimti]

Why is it I get loads of phone calls from companies trying to sell me a new plan around the time my old plan is due for renewal.  How do companies outside of O2 know about my business with O2?

I have already renewed my contract, but am getting sometimes more than daily calls from some company that sounds like its call centre is in India trying to sell me an upgrade.
I have reported them to TPS, but think O2 themselves should be blocking these numbers before they even reach customers
Here is a list of them so far this year
02037693380
02038076376
02038076184

02037690404

02080893450

02037699214

02037693751

02080892462

[madasaf1sh]

@Jimti 

Check your marketing preferences in my o2 and make sure they are set to all off, as otherwise o2's (un)trusted partners will call you 

A lot of them will be scammers, who are just guessing, so block and report for phishing

https://accounts.o2.co.uk/consent

[Jimti]

I checked, and as I suspected, all are turned off already.
It seems odd that they guess just as my contract was due renewal.

[jonsie]

O2 work with third party 'trusted' agents who all have access to O2's data base

This is undoubtably why our data is available to anyone out there and why they know every detail of contract renewal times etc

Take a look at the dozens of approved companies with access to the data

O2 Approved Business Partners | O2 Business