Losing money

What would you say, if your pre-paid electricity has an expiry date? So if you do not use all the units before the expiry date, you lose it? Crazy hey?<br> Why then is it ok for cell phone companies to do this with data / sms / airtime?? I bought it with money which never expires. Isn't that like they are *****ing from me?<br> I just don't understand the concept, and I don't understand that SA can allow this!!<br> I want to upgrade my contract but then would lose all my minutes on my current contract!! I've paid for it...must I just give away money for free??!! It's not that I want to move it over to MTN!!<br> Requested answers at a few shops but no one gets back to me!!<br>