Heya! maxis postpaid and prepaid user here.

Changed my old prepaid (6 years) to a supplementary line, and just got the HYC line today. 4 years validity quite useful. Using it for GSM related electronic projects (I'm a communication engineering student)

Regarding difficulties in sharing top up, its mostly likely a network related issue than a conspiracy. But who knows, businesses would always find ingenious ways get money. Regardless if they are Maxis, Digi or Celcom