so, i got kicked out of the maths and stats program after my first year because i screwed up on the electives. (i did pretty well in all the mandatory courses though)

i have chose b.a in econ as my second year program which i don't really like.

1.) Is there a way I can get back into that program and how?
2.) do you get to choose program again in the third year ? (because I prefer an honour degree rather than just a B.A)

please help me out and many thanks...

You can, just transfer at the end of the year provided you meet to requirements. Email the math department, and find out their exact procedure.

You'll have to do really well, and you'll have to keep up with required courses. What you're doing is called shadowing. Lots of people have do this - check out old threads.