Yeap this been known maxis pass your number and contact to 3rd party agents.

There once maxis 3rd party agent call me asking me whether do i wanna upgrade my line.
They even know what plan you are on but they dont bother to check your bill properly. Just wanna think how to drain you of your money.

My main line RM150 plan every month RM800 then maxis call me whether wanna upgrade to a higher plan to unlimited calls and sms.

My local calls and sms not even RM30 its my roaming calls that expensive.