Telkom RIPOFF

I signed a Smartplan 100 contract with Telkom Mobile on their Summer promotion 28 Sep 2015 & received the my Samsung S6 at about 5pm on Monday 28 Sep 2015. I was absolutely appalled when I received my invoice 4 days later with a amount of R708. Telkom have charged me with R300 for a device installment fee for the month of Sep I would like to mention that I only had the phone in my possession for 2 day 7 hours & now I am being charged an extra R300. Nobody mentioned this to me when I signed the contract. If had I known that this information, I should have just waited 3 day later. I feel so ****** & cheated by telkom as this information was not disclosed to me & I think its is ridiculous that Telkom is not willing to assist. Telkom has great deals but honestly I rather pay more money with service provide that will give me HONEST & quality customer service. Telkom is a ripoff & the sad thing is that I'm now stuck with a 24 month contract .