I got 80% in the mocks and want to bring it up to an A got 85% on the written and got 76% on the listening so just wondering if there is any tips for the letter and the listening because that's where I did the worst
For the listening, the only thing you can really do is listen to previous exam tapes and native Spanish material, such as songs, TV, radio, etc. I'm not familiar with the Spanish exam layout, but if there's several accents and you find a particular one hard, practice that one until you can understand it easily. It sounds like you have good written expression already, so just learn off suitable openings, endings, maybe an idiom or two and grammar rules for the letter and you'll be grand :)
For the letter, the last point is usually give regards to the family but if you just say "recuerdos a tu familia" chances are you're only going to get maybe 2 marks out of 6 if you do higher level. Try to expand! A good point for giving regards to the family is "Recuerdos a tus padres. Saludos a tu abuela. Feliz cumpleanos (sorry don't know how to do squiggly line over n) a tu hermano." If you write that it's a guaranteed 6 marks.
You get 4 marks in total for 1) the address 2)the date 3)Querido/ Querida: and 4) Ecríbeme pronto, Un beso.
For the address remember that the town gets a CAPITAL letter!
For the date pick an easy month such as: 5 de mayo NO CAPITAL FOR THE MONTH
Unfortunately for the other points all you can do is learn past and future tenses as well as you can!