Hidden truth about service

I was adviced to take extended service plan not told im not done paying the last one. Now from Dec they want me to pay double which i cant afford they say they listened to the recording and i was not told it ended so meaning i took the extended plan knowing that im not yet done. My issue is why would i agree when im not done paying and force to pay double. Worst part im very far from next service why rush. If i knew i would have waited to pay up then add extended i feel cheated for sales purposes. And i cant afford double payment