WhaAir conditioning not cooling properly. Temp goes up 3 degrees everytime it kicks on...?

the clunker program will apply to old appliances...uve spent enuff money on this a/c time for a new one...I had a a/c that started to trip fuses after being on for 15 min..the heating and cooling guy said it would be $50 to come out and ess the the problem, normal servicing $45...unseen problems would be extra...I brought a bran new 8,000 btu for $188 at sams club...u do the math..