"GP altered blood results"

had blood test done in 2012. to be told all normal. Only to get sicker and sicker. Then went back had another blood test march 2015. To be told by the nurse taking my blood. Why didn't I have any treatment. in 2012 for the very high tsh level nearly being 12. The nurse then asked the gp why it wasn't treated. The gp rang me recently to tell me they have altered my blood results on the computer to what the doctor thinks. These results have been on my records since 2012 so why has the gp changed them to suit? Is it normal practice for a gp to change results given by the lab. and ignore other consultants advice needless to say looking for new gp. But what chance does a person have if a gp takes it upon themself to change the results given. Something very wrong here and alarm bells are ringing.