My mom died from planocelular tonsilar cancer stage 2, doctor said that she couldn't be saved but i am thinking that if they tried they could help her?

You may be right: Stage 2 cancers are mostly curable. Although a small percentage of them(10-15%) can still prove fatal as they may not respond to treatment. But one must always try to treat early cancers as they are mostly curable. Late stages( stage-4) are sometimes left untreated but tonsillar cancer has high cure rates even for stages 1, 2 and 3.