is it possible to pay for a old contact that was already upgraded

hello<br> <br> can someone please clear something for me, if I did an upgrade and the store messed up ,is it right for me to pay for my old contract still whilst I've just did an upgrade I should pay the old contract till the end date. I have done upgrades before with cellc and Vodacom and I never heard such nonsense. I am very disappointed that in this kind of business people can be so conniving and shrewd. <br> <br> VERY UNHAPPY CLIENT.<br> <br>